


Ground Zero

by concordances



Category: iKON (Kpop)
Genre: Alternate Universe - Time Travel, Domestic, M/M
Language: English
Status: Completed
Published: 2015-11-06
Updated: 2015-11-06
Packaged: 2018-04-29 18:38:09
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 1
Words: 19,558
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5138390
Author URL: https://archiveofourown.org/users/concordances/pseuds/concordances
Summary: <blockquote class="userstuff">
              <p>The day Junhwe dies starts out like any other. The day Jinhwan goes back is a little different.</p>
            </blockquote>





	Ground Zero

**Author's Note:**

  * For [idyleski](https://archiveofourown.org/users/idyleski/gifts).



> Crossposted from [livejournal](http://concordances.livejournal.com/1209.html).

Morning rush hour is a lot worse than Jinhwan remembers it being. The moment he steps into the station, he’s engulfed by the sounds of countless ongoing conversations, every person in sight moving in a different direction. Everything is too loud, too fast, too _much_ — as if someone acquired a remote control to reality and turned every function as far up as possible. It's a complete shock to Jinhwan’s system after sitting around in the silence of his apartment for the last few— weeks? Months? He doesn’t know anymore.  
  
Not for the first time, he wishes he were taller, or at least a little bulkier, with enough weight on him not to get swept halfway across the platform in the wrong direction. He thinks fast, darting onto one of the wooden benches lining the wall. A middle-aged man casts a disapproving look at him, something that might have fazed him under normal circumstances, but Jinhwan’s present position both eases the feeling of claustrophobia and gives him a decent view of the area. An easy win over any shame he might have felt.  
  
The clock mounted on the opposite wall reads twelve minutes after seven. Jinhwan tugs the collar of his coat— no, _Junhwe’s_ coat— up over the lower half of his face, and waits.  
  
Minutes pass. It feels like hours— but no, the clock indicates otherwise. Jinhwan shifts from foot to foot, going over his plan of action in his head. He’s beginning to lose feeling in his legs when spots Junhwe descending the stairs onto the platform.  
  
It’s difficult to distinguish one person from the next at this distance, but Junhwe is a good half-head taller than anyone around him. Jinhwan watches as he tilts his head slightly to talk to someone walking beside him— someone not tall enough to be visible above the sea of heads. Something twists painfully in Jinhwan's gut. Of course. Of course Junhwe wouldn’t be here alone.  
  
But Junhwe will board the train alone, and everything will be okay from there. Jinhwan repeats the words in his head, recites them until they start to mean something different. He shoves his hands deep into pockets to stop them from shaking, knowing it has nothing to do with the cold. Bobby had always said that lying to himself wasn’t Jinhwan’s strongest suit.  
  
Junhwe is waiting on the platform now, with that person. The Other One, Jinhwan decides. It’s a strange feeling, not being the one standing next to Junhwe. Irrational as it is, it’s not a good feeling. Like being locked out of someone else’s life, but still being able to peer through a window and watch them go about their daily routine.  
  
The crown of the Other One’s head is visible from where Jinhwan is standing, his hair windswept and soft-looking. Jinhwan brings a hand up automatically to his own hair, toys with the split-ends. What would Junhwe think of him now? For the first time, insomnia has given Jinhwan something to be thankful for. Exhaustion seems to have dulled his emotions.  
  
Except for fear. The hysteria is ever-present, simmering under the surface, threatening to rise up and spill over at any moment. A reminder that if Jinhwan screws this up, he might never see Junhwe again—  
  
Focus.  
  
_The train is about to arrive at the station_ , announces a tinny female voice. _Please remain behind the yellow line_. Junhwe leans in towards the Other One— a kiss?— but is batted away. There’s a brief flash of disappointment across Junhwe’s face, and Jinhwan’s heart sinks a little in his chest.  
  
There’s no time to dwell on it, though. Jinhwan follows suit as Junhwe boards the train, crossing the platform to get into the same compartment, but through a different set of doors. The last thing he wants is for Junhwe to see him.  
  
The interior of the train is warm. Jinhwan wipes his palms discreetly on his jeans, allowing himself to breathe. Most of the commuters around him are engrossed with their phones. Jinhwan glances around, paranoid, but no one pays him any attention.  
  
He doesn’t know why he does it. Just before the train departs, Jinhwan squeezes his way to the window facing the platform and presses himself against the glass. The Other One is exactly where Junhwe had left him, gazing impassively towards some point in the distance. Jinhwan doesn’t need to see his face to know exactly who it is.  
  
Himself. Kim Jinhwan.  
  
  
  
  
  
  
The day Junhwe dies starts out like any other.  
  
Jinhwan gets up and makes coffee, resolutely ignoring the sounds of Junhwe versus alarm clock back in the bedroom. There's a small stack of plates in the sink— Jinhwan hadn't noticed them when he had come home last night. When he had come home this morning, really, since it had been well past two by the time he had showered and crawled into bed beside Junhwe. A difficult day at the studio, even by his usual standards.  
  
Their routine rarely deviates: Junhwe commutes to SK PlanTech in the morning, a well-known research facility located at the heart of Jongno. Jinhwan spends the latter half of the day coaching aspiring young performers on how to sing and dance in Sinchon. It's an exact non-overlap; Jinhwan leaves the apartment before Junhwe comes home each day, and Junhwe is asleep by the time Jinhwan returns. The only way Jinhwan gets to see Junhwe is if he climbs out of bed an hour before dawn.  
  
Junhwe pads into the kitchen, eyes half-closed with sleep and hair mussed, a reflection of how Jinhwan is feeling. It’s not so much his body but his mind that feels like there’s an invisible blanket draped over it, thick and stifling. Things have felt that way for a while.  
  
Junhwe stops and squints, eyeing the mug in Jinhwan's hand. "Can I have some?"  
  
"No," Jinhwan says, gazing down into the black liquid and wondering if coffee would take faster action if he were to inject it directly into his bloodstream. "You slept longer than I did. And you already drink your entire quota at night."  
  
Junhwe makes a face. “It doesn’t help,” he mutters as he turns to go brush his teeth. Jinhwan laughs against the rim of his mug, but it comes out bitter as the liquid. As a student, coffee had been a permanent fixture on Junhwe’s desk, but not one that had ever prevented him from falling asleep over his textbooks when he tried pulling all-nighters.  
  
Right now there’s no food in the kitchen, which doesn’t matter, since Junhwe has no time for breakfast. He does seem to have enough time to explain the practical evaluation he has at work that day, though, something he insists is a huge bother, but also absolutely necessary for impressing a certain person of important position, since it will determine his future prospects in the company, and also keep him from being fired.  
  
“You should walk me to the station,” Junhwe suggests, as he pulls on his shoes. Casually, as if it’s something he only just thought of, rather than something he’d carefully built their conversation up to. Jinhwan knows him better than that. Junhwe tends to run his mouth when he’s focused on accomplishing something. “You know, as a show of moral support, and all.”  
  
Jinhwan barely registers the request. The words _future prospects_ stir something unpleasant in the pit of his stomach, completely involuntarily. It’s an unsettling feeling, one that seems to have found a home and only grown in the past few months, into something that might now be recognisable as self-doubt. It’s stupid. Junhwe deserves all the support he can get, yet Jinhwan can never quite shake the feeling that Junhwe will always be moving on to bigger, better things.  
  
Jinhwan has done the math. A year lost when he switched majors, another spent looking through classifieds and spending nights on Bobby’s couch. Two and a half years of being a vocal and dance coach. And before that, years of studying for a humanities degree that hadn’t taken him anywhere. It’s completely childish, but Jinhwan can’t deny the frustration he feels. Junhwe’s eyes light up when he talks about his work; Jinhwan knows Junhwe stays late in the labs, even though they never talk about it. It’s as if there’s no place Junhwe would rather be. An entire world that Jinhwan is not only not a part of, but one he _could_ have been a part of, had he not chosen otherwise.  
  
Something must show on his face, because Junhwe quickly changes his tune. “Or you don’t have to come,” he says, a hint of resignation in his voice. “I’ll just. Enjoy the nice weather on my own.”  
  
“No,” Jinhwan says quickly, clamping down on the wave of self-pity. It would be unfair to place blame on Junhwe for Jinhwan’s own shortcomings. “I’m coming.” The self-satisfied smirk on Junhwe’s face is too much to let pass, so Jinhwan adds, jokingly, “For the nice weather.”  
  
It becomes clear how misguided they’d both been once they step outside, the air just short of frosty. Jinhwan is only wearing two layers, and a faceful of wind is enough to make all hopes he had harboured for a good day evaporate. Even Junhwe’s offer to lend him his coat feels like some sort of a jab at Jinhwan’s ability to be an independent, functional human being. Plus, Junhwe hates the cold. Jinhwan shakes his head no, but Junhwe shrugs the coat off and refuses to put it back on.  
  
Eventually, the cold wins over. Jinhwan zips Junhwe’s coat all the way up to his chin and resumes walking in moody silence.  
  
_The train is about to arrive at the station. Please remain behind the yellow line._  
  
“Keep it,” Junhwe says on the platform, when Jinhwan tries to hand his coat back. “I don’t have far to walk.” Jinhwan nods, too tired to argue.  
  
He pushes Junhwe away when Junhwe leans in for a kiss. It’s instinctive, not entirely something he’d meant to do, but he sees the momentary surprise before Junhwe's face closes off. Jinhwan immediately feels bad, apology on his tongue— but Junhwe is already moving to board the train.  
  
"Good luck," Jinhwan calls weakly, making a mental note to make it up to him later. A lack of sleep and growing insecurities are feeble excuses for treating Junhwe the way he has been lately. "You'll do great, don't blow anything up."  
  
Junhwe’s expression doesn’t change, but Jinhwan easily spots the almost imperceptible quirk of his lip. He raises his arm in a wave.  
  
  
  
  
  
  
_“…Six were killed in a series of explosions following a fire at SK PlanTech Corporation on Friday. The accident happened shortly before eleven o’ clock in the morning, and a fire alarm triggered a full evacuation of the compound…”_  
  
  
  
  
  
  
Unlike most days, Jinhwan doesn’t climb back into bed when he returns to the apartment. He can feel the effects of the coffee beginning to wear off; his movements feel more weighted than they had been walking to the station. Nonetheless, he forces himself into a pair of running pants to do warm ups in the living room.  
  
The studio recently hired two new coaches— a former b-boy who specialised in freestyle hip-hop, and a girl who graduated from university the same year as Jinhwan and sang like an angel. Jinhwan had seen them both at work, had been rendered speechless by the sheer effortlessness of their performance. Neither of the two are adept at both singing and dancing. But more than one of Jinhwan’s students had put in a request for a transfer, and Jinhwan had taken to spending whatever free time he could find honing his own skills.  
  
For all their differences, the principles behind singing and dancing are the same: constant practice, maintaining form. A little hard work never hurt anyone.  
  
Jinhwan takes a break a little over two hours into a new routine. He turns on his phone and is in the midst of looking up meat buffets in Hongdae to treat Junhwe to when his phone flashes, indicating an incoming call from an unknown number.  
  
It’s unusual, considering the time of the day. The only ones who ever call at this time are Junhwe (who calls whenever he wants), Jinhwan’s mother (who never did manage to grow accustomed to his working hours), and Bobby (who is prone to irregular bouts of sentimentality, and partial to taking early lunch breaks). All three of their numbers are at the top of Jinhwan’s contact list. Jinhwan hits the ‘accept’ button and raises the phone to his ear.  
  
"Jinhwan?" says the voice at the other end of the line, shaky and distorted with poor reception. "Where are you? I… I couldn’t get to him."  
  
The voice, too, is unfamiliar. "Uh," Jinhwan racks his brains for something he might have forgotten, tries to situate the person’s words in some sort of context. His mind comes up blank. "Get to who? Who is this?"  
  
"It's me," the voice is noticeably urgent. Jinhwan is beginning to think he hadn’t imagined the hysteria there, that it’s not just the result of static. The person on the other end of the line sounds panicked and short of breath. "It's me, Donghyuk."  
  
"Donghyuk?" Jinhwan quickly runs through a mental list of some of his closer friends from middle and high school. The name doesn’t ring a bell; he’s fairly certain he doesn’t know a Donghyuk.  
  
He’s about to inform the poor guy that he must have somehow dialled the wrong number, when he stops. The first thing the person— _Donghyuk_ — had said when Jinhwan had picked up was Jinhwan’s name. Donghyuk seems to know him. Not a mistake, then.  
  
“Uh,” Jinhwan says again, this time more uneasily. This entire situation is like something straight out of a thriller film. “How did you get my—”  
  
“I couldn’t get to Junhwe. I think he—” the rest of Donghyuk’s words are indecipherable, drowned out by the sounds of raised voices in the background.  
  
“What?” Jinhwan asks, heart skipping a beat. “What happened? Is Junhwe okay?”  
  
And then the name clicks. Jinhwan _does_ know a Donghyuk, just not from where he’d expected. A simple case of miscontextualisation; Donghyuk is Junhwe’s colleague, the one who apparently doesn’t know how to shut up, but also regularly covers for any screw ups Junhwe makes in the lab. Junhwe has talked about him on multiple occasions.  
  
“Explosion,” Donghyuk says, voice wavering. “In the East block. Didn’t you hear?”  
  
There’s a sharp intake of breath. It takes a moment for Jinhwan to realise the sound came from him. There’s no one else around, after all.  
  
The room is suddenly very cold.  
  
“Explosion?” he echoes, entire body gone numb. He can hear himself talking, though he no longer knows what he’s saying. His mouth seems to be moving on its own accord. “What are you saying?”  
  
If anything happened to Junhwe, anything at all—  
  
“I left the room to get something and when I got back—” Donghyuk babbles. “I didn’t know anything would happen, he won’t answer his phone and I...”  
  
“Is this some kind of joke?” Jinhwan snaps, despite himself. The outburst seems to surprise Donghyuk, who falls silent. It surprises Jinhwan, too. It’s not like him to lose his cool, and Donghyuk had sounded perfectly sincere, but _this_. SK PlanTech is a highly reputable corporation. An accident like that just wouldn’t make any sense. More importantly, _Junhwe_ —  
  
It can’t be true. It’s impossible.  
  
And yet, wherever Donghyuk is making the call from sounds like it’s in utter chaos. Frantic voices are audible in the background— someone is yelling— and is that the faint wail of a siren? The beginnings of dread start to pool in Jinhwan’s gut. It sounds exactly like the site of an accident.  
  
“Joke?” Donghyuk sounds on the verge of tears. “ _You’re_ the one who—”  
  
Making a snap decision, Jinhwan ends the call.  
  
His heart is thudding in his chest as he dials Junhwe’s number. He doesn’t even realise what he’s doing until he hears the ringing on the other end of the line. _Please_ , Jinhwan thinks desperately, _pick up_.  
  
It rings once, twice, three times. No answer.  
  
Jinhwan swallows. The prospect of work suddenly seems trivial. There isn’t any way to confirm that it’s a false alarm, that Junhwe is fine, so Jinhwan grabs his wallet and pulls on the first coat he lays his hands on. Junhwe _has_ to be fine. The alternative is unthinkable.  
  
He flags down the first taxi he can find. The driver doesn’t look pleased about running red lights just to get to their destination as fast as possible, but few people can say no to a wallet-full of cash.  
  
  
  
  
  
  
_“…. Witnesses reported hearing a blast following the sounding of the alarm. As of now, five of the deaths are suspected to be employees at the facility, with one body as of yet unidentified. The confirmed victims include Park Byungjun, Lee Jaemin, Koo Junhwe…”_  
  
  
  
  
  
  
Jinhwan remembers the building. A section one of the East block is charred beyond repair, edges of concrete exposed from the blast. Someone in his periphery murmurs about the fourth and fifth floor labs having been completely destroyed. It looks as if someone, or _something_ , a hundred times larger than a human, had punched a hole through the corner of the building. People in heavy gear and helmets are congregated near the entrance. Debris litters the area.  
  
The evacuated employees are gathered a short distance away from the facility, which has by this point been cordoned off. Jinhwan remembers meeting Donghyuk, whose face is stained with tears and won’t stop saying _I’m sorry, I’m sorry_. People— employees, bystanders, police— come and go. Eventually, Jinhwan is led away. There isn’t anyone left in the buildings, they tell him.  
  
He doesn’t remember much after that. He sits motionless, for what feels like hours. Someone asks him to help identify Junhwe’s phone— it’s a little worse for wear, the case and screen scratched, but unmistakably Junhwe’s. People are talking in low voices, and Jinhwan feels dizzy under sterile white lights.  
  
Hanbin is sitting next to him, Jinhwan’s right hand clasped lightly between both of his. It’s funny, because Hanbin is supposed to be in Gwangju. He’s casting Jinhwan glances every so often, the kind that means he wants to say something reassuring but can’t find the right words, and Jinhwan wants to tell him he’s fine, he’s okay, only it’s as if he’s forgotten how to form sounds.  
  
Jinhwan continues to wait. Junhwe doesn’t show up, and all Jinhwan can think is that Junhwe would never leave him to worry like this, not even for his job. In retrospect, there had been few things Junhwe wouldn’t do for him. And Jinhwan…  
  
Jinhwan had done so little, comparatively. It’s funny, because Junhwe’s emotional ineptitude had always been the thing people saw as a potential roadblock to their relationship, when really Junhwe is easy to read as a book, if you know what to look for. Jinhwan isn’t so sure the reverse applies. He’d let his own baggage weigh them both down, hadn’t said some of the things he should have.  
  
Surely, Junhwe must know how much he means to Jinhwan. Surely.  
  
_I’m sorry for your loss_ , a stranger’s voice says, and then it’s final. Junhwe isn’t going to walk through the door, put an arm around him, and tell him to stop worrying so much. Junhwe is gone.  
  
  
  
  
  
  
The refrigerator door makes a clinking sound as it’s shut, an indication that Bobby has filled it with food supplies. A departure from the usual state of affairs in the apartment.  
  
They take turns hanging around, Bobby and Hanbin, dropping the occasional subtle hint that Jinhwan should consider moving out. Some sort of metaphor for moving on, plus the apartment will probably be difficult to maintain. Jinhwan could always crash with them if he wants to, they remind him.  
  
There’s a carton of something in front of Jinhwan. It looks like Chinese takeout, from the restaurant down the road. Junhwe likes the food there— liked the food there?— especially the sweet and sour pork. It’s a little on the pricey side, so they’d only buy from there maybe once or twice a month.  
  
“Eat,” Bobby says, in the way that only Bobby is gentle.  
  
Jinhwan eats.  
  
They don’t mention that Jinhwan hasn’t spent more than a couple of seconds in any room besides the living room since the incident. Jinhwan appreciates it, really. It’s the first time since Hanbin graduated that they’ve spent more than a single weekend together, and he feels bad for being such terrible company.  
  
  
  
  
  
  
Fueled by some unexplainable, masochistic urge, Jinhwan tunes in to every news broadcast that covers the accident. The reports are all the same— read out in painfully detached voices, news anchors’ expressions devoid of any real emotion. Every one of them throws around phrases like _repercussions_ and _future safety measures_ , sparing the casualties a mention in passing. _Five bodies identified_. It fills Jinhwan with a slow, quiet anger, the knowledge that the media is able to so easily sum up the end of Jinhwan’s life as he’d known it. A body count. Nothing more.  
  
On the third day, Jinhwan rips through the wires connecting the television to the wall. Bobby is alarmed and Hanbin can no longer watch late night drama re-runs, but at least Jinhwan’s head stops hurting after that.  
  
  
  
  
  
  
_“...Several blocks in the East section of the compound incurred significant damage by the blast. The cause of the explosion is still not known, and investigations are ongoing…”_  
  
  
  
  
  
  
There’s a small box of Junhwe’s possessions on his desk, items that had been retrieved from his work station after the accident. Jinhwan waits until neither Hanbin nor Bobby are around to go through it. He finds Junhwe’s lab coat and work pass, and right at the bottom of the box, a stack of papers with Junhwe’s handwriting on them. And then everything changes.  
  
The papers are notes, filled with diagrams and calculations. Pages and pages of them. Junhwe had carefully dated every one of them, so it’s apparent that the papers in front of Jinhwan are the result of several years of work. Finally, an explanation for why Junhwe never finished any of his important university assignments on time. Jinhwan tries not to let the fact that Junhwe hadn’t told him about something seemingly major bother him.  
  
Jinhwan is no physicist, but a year of core classes and three of reading Junhwe’s notes is a huge step up from nothing. He pores over everything, from the relativity of simultaneity to theories about overriding violations of causality, telling himself the entire time that he's trying to bridge a gap between them, trying to understand what clearly meant something to Junhwe. Junhwe’s handwriting is familiar— the way his letters loop and words become a scrawl when he’s excited. Every moment Jinhwan is reading, it’s as if Junhwe is still alive. Like he exists in a time frame not confined to the past.  
  
Not being able to sleep is very suddenly no longer a detriment. Jinhwan reads for days at a time, the colour of the sky outside the only indication that time is passing at all. The notes take weeks to make any sense of. When he’s finally made it through them all, Jinhwan reads everything again, just to be sure. And then he knows what he has to do.  
  
The first step towards acceptance is acknowledging that the given situation isn’t a bad dream. Soon after Jinhwan stops believing Junhwe will reappear, however, Jinhwan stops believing that things will get better at all. Everything about the reality he’s living is wrong. There are too many things Jinhwan wishes he could change.  
  
Carrying on like this, without Junhwe, is too hard to imagine, so Jinhwan decides that he’s not even going to try. Instead, he’s going to go back and save him.  
  
  
  
  
  
  
Three things become apparent once Jinhwan arrives at SK PlanTech, having trailed Junhwe from the station. The first is that the facility is a lot larger than Jinhwan had pictured it to be, which is something, considering Junhwe had described every detail about the place when he had first started working there— from the bridge-like structures connecting adjacent buildings to the placement of water coolers on the seventh floor. The compound is vast, more like a small town than a mere collection of blocks.  
  
The second is that Junhwe had lied— the walk from the station to the facility is, by no stretch of the imagination, a short one. Jinhwan steels himself against both the weather and a mounting sense of panic as he maintains a fifteen meter distance between himself and Junhwe, trying desperately to keep Junhwe in sight while trying not to look like he’s trying. By the time Junhwe steps through the glass doors of the main entrance, ears pink from the cold, Jinhwan is too out of breath to feel relieved. He darts after him into the building, head bowed.  
  
The third, and most worrying, is that Jinhwan doesn’t actually know where to go from here. In his head, his brief plan of action had gone from ‘locate Junhwe at the station’ to ‘follow Junhwe to work’ to ‘save Junhwe’. Now that he’s made it to the facility, Jinhwan realises he doesn’t have the slightest idea where to begin. He knows the accident happens on the fourth or fifth floor of one of the East blocks, shortly before eleven. The most sensible course of action would probably be to keep Junhwe as far away from that area as possible— Jinhwan might even be able to accomplish that without revealing that he’s been here at all.  
  
But.  
  
The accident had killed more people than just Junhwe. To make sure Junhwe alone steers clear of the block before noon would be to let the others die, others who must have meant as much to someone as Junhwe does to Jinhwan. Jinhwan chews on his lower lip. He’s here to save _Junhwe_ , he shouldn’t be worrying about anything or anyone else. But how do you weigh one life against others?  
  
The battery bar displayed on the screen of his phone is red, indicating that it needs a charge. Jinhwan pretends to be checking emails on it and watches the steady trickle of employees heading for the far left of the building, Junhwe among them. The glass doors lead to a lift lobby, and the sign on the wall next to them reads _West Block_.  
  
Junhwe doesn’t work in the East block, Jinhwan realises. Junhwe had an evaluation the day of the accident. _That_ must have taken place in the East block.  
  
If anything, this new piece of information makes Jinhwan’s job easier. If Junhwe isn’t stationed in the East block, then he doesn’t _have_ to be there. It shouldn’t be difficult to get him to avoid the area. But Jinhwan’s hands are shaking again, because therein lies the issue. Junhwe never _had_ to be in the East block. It had been pure bad luck. His evaluation could have been in any block, on any day, but it _had_ to be in the East block on that morning in November, it _had_ to—  
  
Jinhwan takes a deep breath.  
  
A woman shoots him a concerned look as she passes, and Jinhwan shoves his phone into his pocket and tries to remember how to work the muscles in his face to smile. She’s gone before he can get it right, though, and Jinhwan hastily makes his way over to the lift lobby Junhwe had gone into. He’s stalled long enough that the stream of arrivals has tapered off, the atrium having gone quiet in a span of minutes.  
  
Everything will be fine, Jinhwan tells himself. Except that he’s come to realise ‘save Junhwe’ and ‘stop the accident’ are synonymous, and Jinhwan doesn’t know what could cause an explosion in a lab, let alone how to stop one.  
  
The lobby is the sort that requires employees to tap their pass for access. With a confidence he doesn’t feel, Jinhwan pulls Junhwe’s work pass from his pocket, the one he’d retrieved from Junhwe’s possessions, and taps in. Then he slings the lanyard around his neck, making sure the side of the pass with Junhwe’s photo and name visible is face down.  
  
It’s almost surreal, stepping into an empty lift with no idea what to expect or do when he steps out. Jinhwan’s finger has barely made contact with the seventh floor button when a voice shouts, “Wait, hold the door!” and someone stumbles in. An employee, no older than Jinhwan, who almost runs into the opposite wall of the lift from the momentum. He doubles over to catch his breath, but not before nodding at Jinhwan in thanks.  
  
“Sorry,” he gasps, eyes still on the ground, and Jinhwan is stricken by how familiar his voice is. “I’m not usually late for work, but my train was delayed by ten minutes this morning, and just my luck, too— I was supposed to come into work early today, I promised someone I would do something for them.” He finally rights himself, finger hovering over the seventh floor button when he realises it’s already been pressed. “Oh, I’m going to the seventh floor too, are you…” he turns to look at Jinhwan for the first time, eyes going wide.  
  
“ _You_ ,” he says.  
  
“Me?” Jinhwan stutters, voice hoarse from disuse. It’s the first word he’s said to anyone in days, probably. To say there hadn’t been anyone to hold a decent conversation with would be a lie, but everything had become more effortful since the accident.  
  
The person in front of Jinhwan doesn’t look the slightest bit familiar, but certainly sounds it, and seems to recognise him on top of that. Jinhwan racks his brains for someone he might have forgotten, quickly running through a mental list of some of his closer friends from middle and high school— but wait. He’d done something like this recently. It had been when he’d talked to—  
  
“Donghyuk,” Jinhwan whispers.  
  
  
  
  
  
  
The kitchen light is on when Jinhwan finally gets back to the apartment, exhausted from running extra classes at the studio. Spring auditions are just around the corner, and half the students at the academy had requested extra training; weekday classes had been extended three hours per day, with all instructors having to take on extra loads.  
  
Jinhwan should have waited until he was indoors to take off his coat— the stairwell had been chilly, a bad combination with a sweat-soaked t-shirt. He winces now at the sensation of the material against his back, cold and wet, the furthest thing from comfortable. One of his sneakers hits the wall as he toes it off, and Jinhwan drops his bag by the door.  
  
Junhwe is asleep at the table, half-drunk mug of coffee in front of him and phone in his hand. He looks uncharacteristically tranquil, eyes closed and breathing even, and Jinhwan feels so drained that he momentarily considers pulling up a chair and joining him. One of them has to be the Responsible one, though, so Jinhwan carries the mug to the sink, and when he returns, Junhwe has one eye cracked open.  
  
Jinhwan reaches over and brushes the hair from Junhwe’s forehead, runs a thumb lightly over his cheek. “Hey.”  
  
“Hi,” Junhwe mumbles, and really, he’d probably be upset if he knew how cute he looked like that. Jinhwan takes a step back as Junhwe sits up and stretches, a hand coming down automatically to fix his hair. Jinhwan grins, shaking his head when Junhwe beckons for him to come back over.  
  
“You don’t want me near you,” Jinhwan warns. “Trust me, I’m gross.”  
  
Junhwe pulls a face. “No you’re not,” he says, in an exaggeratedly patronising voice. “You’re fine. You’re per—”  
  
“You should’ve gone to bed,” Jinhwan cuts in, trying not to laugh. “I told you not to wait up.”  
  
Junhwe frowns, dangerously close to a pout. “Didn’t want to. I…” his eyes flicker to his phone, still clasped in his right hand. He sits up straight and suddenly looks a lot more awake than he had a few second previous. “Hey. Guess what?”  
  
The look on Junhwe’s face is a mix of emotions Jinhwan can’t read. “What?” Jinhwan asks, suddenly nervous.  
  
Junhwe unlocks his screen and turns it around to show Jinhwan the email displayed on it. _Job Offer — SK PlanTech_ , reads the subject title, and Jinhwan’s heart jumps in his chest.  
  
“Dear Mr. Koo Junhwe,” Jinhwan reads, almost tripping over his own words in an attempt to speed through them and get to the point. “We are pleased to inform you that you have been accepted for the position of— oh my god. You got the job.”  
  
Junhwe beams at him, and Jinhwan’s heart feels like it’s about to explode in his chest. “I’m— wow,” he says, giddy with excitement. “I’m so happy for you. I would give you a hug if I weren’t so sweaty.”  
  
Junhwe is quick to pick up on the generosity. “There are other ways you could congratulate me,” he says, wiggling his eyebrows suggestively.  
  
To his credit, Jinhwan is tempted to agree to whatever Junhwe has in mind. But then he takes a step forward and feels light-headed from how tired he is. “Ha, that’s an idea. But you know, I really need a shower.”  
  
The sort-of-rejection doesn’t seem to dampen Junhwe’s good mood in the slightest. “Can I come?” he asks.  
  
“No,” Jinhwan says, turning around to go to the bathroom. “Some of us actually have jobs that we’ve already started, that we have to get up tomorrow for, and— _a_ _ck_.”  
  
He isn’t expecting Junhwe to practically slam into him from behind, wrap his arms around Jinhwan’s middle and bury his nose in Jinhwan’s neck.  
  
Jinhwan opens his mouth to say something, but words fail him.  
  
“Ugh,” Junhwe says, after a beat. “You were right. You really are gross.”  
  
He shifts against Jinhwan’s back, and Jinhwan is sure three showers won’t get rid of the feeling of his soggy t-shirt moving between them. “Junhwe…”  
  
“So gross,” Junhwe continues. “That I need a shower. Immediately. Like, right now.”  
  
Jinhwan reaches around with his left hand and tries to jab Junhwe in the ribs. He misses. Nothing can ruin the fact that Junhwe had gotten the job, though— the best known research corporation in Seoul. Something he’d worked so hard for.  
  
“If I weren’t so proud of you right now…” Jinhwan leaves the sentence hanging, in the hopes that it will sound threatening. Unfortunately, Junhwe doesn’t appear very threatened.  
  
“I don’t think there’s enough hot water for the both of us,” Junhwe muses. “I guess that means we’ll have to be quick.” He shuffles halfway to the bathroom, then shuffles back when he realises Jinhwan hadn’t followed. “Are you coming?”  
  
Jinhwan sighs loudly, but bows his head to hide a smile.  
  
  
  
  
  
  
Donghyuk looks taken aback. “You know me?” he asks.  
  
A soft _ding_ indicates the lift has arrived at the seventh floor, interrupting their exchange. Donghyuk steps out into the empty lobby and Jinhwan follows automatically, stopping only when Donghyuk turns.  
  
“I, uh,” Jinhwan tries to think of why he shouldn’t know Donghyuk, which isn’t that difficult a question to answer. The only reason he recognises Donghyuk— his voice, to be exact— is because he’d spoken to him over the phone in the hypothetical future. So really, he shouldn’t be able to recognise Donghyuk at all at this point in time.  
  
Jinhwan isn’t sure what shows on his face, but Donghyuk looks bemused by the silence. “What,” he says, a tentative grin spreading across his face. “Does Junhwe talk about me, or something?”  
  
Jinhwan latches on to the idea. “Yeah,” he says quickly, and it’s not a lie, not really. “I’ve… heard a bit about you. Nothing bad or anything, just…”  
  
“That I talk too much?” Donghyuk finishes, grinning. It doesn’t sound like a compliment to Jinhwan, but Donghyuk seems almost to take it as one. Jinhwan nods mutely.  
  
Donghyuk mirrors the motion. “Well, I know who you are,” he says, all previous fluster over his lateness apparently forgotten. “Pretty much our whole lab knows you, Junhwe doesn’t stop talking about you. And he says _I_ don’t shut up.”  
  
A wave of something sweeps through Jinhwan, starting from the pit of his stomach— something that feels a lot like guilt. He’d grown accustomed to avoiding questions from colleagues about his personal life; he’d probably mentioned Junhwe only once or twice as the flatmate he’d known since university. It wasn’t that he was ashamed of admitting to their relationship. It had just been far easier not to. Junhwe had been different, of course. In all the years they’d known each other, he’d never actually gotten the hang of self-censoring.  
  
Jinhwan had, over time, come to assume that his relationship with Junhwe, and Junhwe’s relationship with his job, were not only separate and distinct, but incompatible. It’s a lot easier to admit now that Junhwe talking about his latest projects at the lab always stirred some sort of anxiety in Jinhwan. That a small part of Jinhwan, a part he tried his hardest to deny, had been afraid that Junhwe looked forward to leaving the apartment each morning. That he valued his work over just about everything— and everyone— else in his life.  
  
It seems almost silly, now.  
  
“So it’s kind of like I’m meeting a celebrity,” Donghyuk continues, oblivious to the emotions Jinhwan is trying to keep in check. “What are you doing here, anyway? Did you bring something to give to Junhwe? Because I could help.” He seems finally to take notice of Jinhwan’s expression. “Um. Are you okay?”  
  
Jinhwan gathers himself, draws a shaky breath. Donghyuk looks alarmed.  
  
“I’m fine,” Jinhwan mumbles, “I’m just… It’s just the cold. I’m okay.”  
  
Donghyuk nods, though the skepticism lingers in his eyes. “Oh,” he says suddenly, as if coming to a realisation. “Are you here to help Junhwe move some of his stuff? I thought he wasn’t leaving for a few more weeks.”  
  
His words take a second to sink in. “Leaving?” Jinhwan blurts, before he can stop himself. It feels like the phone conversation they’d had on the day of the accident all over again. Donghyuk dropping bombshells while he struggles to keep up. “Leaving to go where?”  
  
The smile seems to slide off Donghyuk’s face. “Wait, you didn’t know he was leaving?” There’s a momentary pause, in which Donghyuk raises his hands to his hair as if he’s going to tug on it, then seems to change his mind and leaves hovering in mid-air. “Fuck. He’s going to skin me.”  
  
For the second time this conversation, Jinhwan feels like he’s had the wind knocked out of him. “Junhwe is quitting?” he asks weakly. “ _Why_?”  
  
It could just be hindsight bias, but Junhwe _had_ seemed restless in the handful of weeks leading up to the accident. As always, though, Jinhwan hadn’t acted on it. Junhwe never made a big deal out of Jinhwan’s occasional moodiness, so it seemed fair to give Junhwe his space. Now, it just seems like he’d been negligent.  
  
Jinhwan feels sick. He’s tired of feeling guilty, of always being the one who hadn’t tried hard enough. If they were still in university, nothing like this would ever have gone unresolved. The knowledge that Junhwe had kept something huge like quitting his job from Jinhwan stings. It’s absurd, especially when Junhwe seemed to be making such good progress within the company. Jinhwan can’t imagine what might have triggered the decision. And then there had been that stack of papers, the ones that had brought Jinhwan here. How many more secrets had Junhwe kept from him?  
  
Donghyuk looks guarded, shoulders tense, avoiding Jinhwan’s gaze. “I— you know what. I shouldn’t say anything. You should just… talk to him, maybe.” He glances around, eyes coming to rest on the digital clock on the wall adjacent to the lifts. “I have to go,” he says hurriedly. “I was supposed to help Junhwe with his evaluation prep. Sorry for…” he makes a vague gesture with his hands, then turns to leave.  
  
“Wait,” Jinhwan says.  
  
Donghyuk could help, Jinhwan realises. Donghyuk _knows_ Junhwe, Donghyuk is his colleague. From what Junhwe had said the handful of times he’d mentioned Donghyuk, Donghyuk had sounded like a friend. This might not work, but Donghyuk is the best chance he’s got.  
  
“I need a favour from you,” Jinhwan says. Donghyuk’s eyes flicker to the door, but he doesn’t move. Jinhwan takes a deep breath. “No matter what happens, don’t let Junhwe go for that evaluation today.”  
  
Donghyuk stares at him, dumbfounded. “Don’t let him— what? Why?”  
  
Getting Donghyuk to look out for Junhwe while Jinhwan looks for the source of the accident is the best way to make sure no harm comes to Junhwe, Jinhwan decides. If Donghyuk doesn’t manage to keep Junhwe from going to the East block, hopefully Jinhwan will be able to get to the source first. If Jinhwan can’t figure out how to stop the accident, there will still be a chance Donghyuk will manage to keep Junhwe away. A double safeguard.  
  
The East block labs make up the danger zone. Junhwe can’t be there if and when the explosion goes off. Jinhwan, on the other hand…  
  
“It’s important,” Jinhwan says, with a conviction surprising to his own ears. “It’s really, really important.” For a moment he almost loses his nerve, stumbling over his next words. “Promise me you won’t let him go near the East block. Please.”  
  
Donghyuk’s expression is uneasy. “If this is, uh, some kind of a revenge plot…” but even as he says it, he seems to deflate, looking at Jinhwan warily. Maybe he’d felt some sort of sincerity coming from the request. Or maybe Jinhwan seems desperate enough to make his cause compelling. Jinhwan doesn’t know, hadn’t even realised he’d been holding his breath until Donghyuk opens his mouth to answer.  
  
“I don’t know what you’re trying to do,” he says, eyebrows knitted together. “But fine. I’ll do it. But only because Junhwe speaks so highly of you, and I’m impressionable.”  
  
Relief floods through Jinhwan, a first since he’d set out on this task. He nods, not trusting himself to speak, then gestures towards the phone visible in Donghyuk’s right pant pocket and sticks out his hand.  
  
Donghyuk hands his phone over without question. Jinhwan keys in his number, saves it under ‘Jinhwan’. “If anything happens,” he tells Donghyuk. “Call me.”  
  
Donghyuk nods his affirmation, unexpectedly composed for someone who’d just been enlisted in sabotaging their colleague for no apparent reason, and who’s now almost twenty-five minutes late for work. He turns to leave for the second time, but is stopped by Jinhwan a last time.  
  
“Donghyuk,” Jinhwan says. Donghyuk looks back questioningly.  
  
Jinhwan wants to make Donghyuk understand. He wants to tell him that Junhwe means the world to him, that Jinhwan would never want anything again if it meant he could keep Junhwe safe. That he wants so badly to go up to Junhwe right now, explain everything to him, take him home. That he has to try stopping the accident nonetheless. That he’s scared.  
  
But Donghyuk is a stranger, someone he’d met only fifteen minutes ago. Not someone who knows what it feels like to live in world without Koo Junhwe. At least, not someone who does yet. And hopefully someone who never will.  
  
Jinhwan’s tries to ignore the sting in his eyes. “Thanks,” he says instead.  
  
  
  
  
  
  
The interior of the apartment looks particularly lived in, or like it might otherwise have been the host of one too many parties— the front door has a huge splinter running up its side, a small chunk of the wood missing from its base. The wallpaper in the main room is yellowed, peeling, and outright torn out in several places. One of the bulbs is blown, and there are faint, unidentifiable stains visible on various parts of the floor.  
  
Jinhwan watches as Junhwe’s eyes scan the area carefully, from the couch to the narrow hallway to the kitchenette. The place is small, not at all classy, but still livable, especially for its price. The wallpaper and stains and light bulbs can all be cleaned up or replaced. All things considered, it’s a reasonable place for two graduates trying to find their feet.  
  
“The rent is cheap,” Jinhwan explains. “It’s not much, I know.”  
  
“It’s perfect,” Junhwe breathes. Then he seems to catch himself, cheeks colouring slightly. “I mean, it’s— yeah. It’ll do. The station is like, ten minutes away.”  
  
Jinhwan nods, oddly relieved. He shoves his hands into his pockets and walks over to the window at the far end of the room, peering out of it. There’s not much of a view to speak of. “It’s nicer in the day, really it is. There’s a convenience store right across the road, too.” He turns to look at Junhwe. “So we’re good to go?”  
  
The smile that spreads across Junhwe’s face is a tentative one, almost as if he doesn’t believe any of this is actually happening. It reminds Jinhwan of the way he used to be when they’d first started going out, fumbling and awkward. but incredibly endearing.  
  
“Are you sure?” Junhwe asks, in a rare moment of uncertainty. “About,” he makes a sweeping motion with his arm. “This. Everything?”  
  
Jinhwan is reminded of how much of a big deal this is to Junhwe. Like with anything else he’s even the remotest bit unsure about, Junhwe had avoided the subject of moving in together entirely. It had been Yunhyeong who had brought the matter to Jinhwan’s attention.  
  
“No, I’ve changed my mind, I’m going to ask Chanwoo to live with me instead,” Jinhwan says. “Don’t be ridiculous. Of course I’m sure.”  
  
Junhwe looks more affronted than embarrassed. He recovers quickly, brushing it off and, predictably, sidling up to Jinhwan’s side and slinging an arm around his shoulder.  
  
“So you can’t live without me?” he asks, eyes bright. “Because you _looove_ me?” Something he’d picked up from Bobby, Jinhwan is sure, and for the specific purpose of ensuring Jinhwan would never make him sit through another dinner with the older boy again. Any existing tension disappears from the room.  
  
Jinhwan eyes him, trying to keep a straight face. “I don’t know how you came to that conclusion? That’s not what I said at all.”  
  
“But it’s true, right?” Junhwe presses.  
  
“Yes,” Jinhwan concedes, after a moment. “I suppose.”  
  
Junhwe looks satisfied.  
  
Jinhwan laughs despite himself, reaching for the hand Junhwe has around his neck and interlacing their fingers. “Bobby’s giving up the apartment soon, so I’ll be moving my stuff,” he says, nudging Junhwe gently in the side with his elbow. “Once you graduate, this’ll be it.”  
  
“Which is like, months away,” Junhwe grumbles. “Can’t I just move in right now?”  
  
“It’s too far from campus,” Jinhwan points out. “You’d have to wake up at, what, six in the morning to get to class?”  
  
Junhwe makes a face. “You don’t think I’d wake up at six in the morning for you?”  
  
Jinhwan disentangles his fingers from Junhwe’s and turns so that he’s facing him, reaching out to pat Junhwe on the cheek. “I don’t think you’d wake up at six for class. Stay in school, you delinquent. Study hard so you can help me pay rent.”  
  
Junhwe looks like he’s about to argue, but reconsiders and closes his mouth. When he speaks, it’s with a tone he doesn’t often use, deliberate and thoughtful.  
  
“I’m going to go work at SKP,” Junhwe says, something like resolve flashing in his eyes. “Biggest physics research center in Seoul. It’s supposed to be hard to get a job there, but that’s what I’m going to do. Work in their labs, do experiments, invent things.” He grins. “Like a real scientist.”  
  
Jinhwan believes Junhwe can do it. He smiles, getting on tiptoe to plant a kiss on Junhwe’s mouth. “You do that.”  
  
  
  
  
  
  
Stepping into the fourth floor hallway of the East block is like stepping into a different world. The first thing Jinhwan notices is the smell— clean and sterile. Not quite like a hospital, but close. The hallway is wide, extending in both directions, doors visible on either side. There’s a signboard directly opposite the door to the lift lobby, indicating which way to go to get to which lab.  
  
Out of the corner of his eye, Jinhwan sees someone heading in his direction. It’s probably just an employee with somewhere to be, but even so, Jinhwan feels his heart rate pick up. He closes the distance between the signboard and himself in three strides, getting up close and studying the words printed on it, trying to look inconspicuous.  
  
He had, perhaps naively, expected the initial fear that came with walking into the facility to ebb away after a while. But ever since setting foot in the station in the morning, it had felt like there was something pulled taught in the vicinity of his stomach, a buildup of anxiety. Trying to ease the tension only leaves him feeling weary and tired, and Jinhwan doesn’t know which is worse.  
  
The person in the hall with him— a woman wearing a lab coat, from the looks of it— walks by without issue. Jinhwan lets out the breath he’d been holding and tries to get himself to relax. It has the opposite effect, unfortunately, since he can’t think of anything worth being calm about. Encountering Donghyuk in the West block, no matter how much of a surprise, had at least provided a temporary distraction from his situation. Worrying about things like where he should go next, how not to look like a lost intern in desperate need of directions— and what _would_ happen if Jinhwan were to get caught with Junhwe’s pass? _I’m here from the future to stop a fatal accident_ doesn’t sound like something that would go down well with anyone.  
  
The back of Jinhwan’s neck is prickling, as if he’s being watched. His real task has only just begun, and already paranoia has set in. It would look suspicious to turn to check, so Jinhwan clamps down on the feeling and goes left.  
  
It doesn’t matter that every door he passes is labelled— none of them are open, so whatever and whoever is behind them remains hidden from view. Jinhwan keeps his head down as he walks, making sure to avoid eye contact with anyone he passes. He thinks back on the year of physics he took in university. Unlike the other sciences, physics doesn’t involve chemicals, but there must be other ways to set off an explosion. Some sort of thermodynamics experiment, electricity from circuits, maybe even a steam generator…  
  
Jinhwan doesn’t realise he’s turned the corner until a noise prompts him to look up, and he’s faced with a different, unfamiliar hallway. The noise had come from behind him, and sounded like— but no, that can’t be right. He must have imagined it.  
  
Jinhwan has taken two steps forward when he hears it again, clearer this time.  
  
“ _Jinhwan_.” A low hiss, voice unrecognisable.  
  
Jinhwan turns, bewildered, searching for the source. There’s a door in the corner that had hadn’t noticed before; the sign on it indicates that it leads to a stairwell. The door is ajar.  
  
With a quick glance around to make sure no one is looking, Jinhwan walks over to the door, not knowing what to expect as he pushes it open and slips inside.  
  
He’s certainly not prepared for who he sees standing in wait for him, arms folded low across his chest.  
  
“Yunhyeong,” Jinhwan breathes. He’s surprised he manages to make a sound at all. His head is hurting again, the slow throbbing that had started up shortly after the accident. Yunhyeong being here doesn’t make any sense. Especially since— “You don’t work here,” Jinhwan accuses, voice strained. “I know you don’t.”  
  
Yunhyeong looks no different from the last time Jinhwan had seen him, well over a year ago. He has the same good looks, his face slightly more matured, if anything. When he answers, it’s with words that seem to have been carefully weighed.  
  
“True. But neither do you.”  
  
Jinhwan says nothing. Junhwe had been closer to Yunhyeong at university, since they shared a major, but all three of them had studied together often when they’d all still been in school. Junhwe never talked about it, but Jinhwan suspects something happened between him and Yunhyeong in their final year— a falling out, or something like it. Junhwe hadn’t met up with him since graduation, and by association, neither had Jinhwan.  
  
Jinhwan hesitates, and Yunhyeong reaches forward. Before Jinhwan can react, Yunhyeong takes the pass hanging from Jinhwan’s neck in his hand and studies it.  
  
“Koo Junhwe,” Yunhyeong reads, eyes flicking upwards to look at Jinhwan. There’s a familiar trace of humour in them, and Jinhwan feels like crying. “You look different from the last time I saw you.”  
  
It’s such a Yunhyeong thing to say, which is comforting in a strange way. Sentimentalities aside, Jinhwan still doesn’t know what’s going on. “Yunhyeong,” he starts, trying to ignore how tired and defeated he sounds. “What are you doing here? How did you even get in?”  
  
Yunhyeong seems to take this in, contemplating for a split second before saying, “I talked to people. You’ll be surprised at how friendly people are to a newbie without a card.”  
  
Charmed his way around, then. Yunhyeong had always been modest, despite his popularity. He never used to flaunt his looks at university, even though he had a tendency to flirt a bit. The more pressing question, however, he’d left unanswered.  
  
“What are you doing here?” Jinhwan repeats.  
  
Yunhyeong's brow furrows. “The reason I’m here” he says slowly. “Isn’t so different from why you’re here.” Then, watching Jinhwan’s expression very carefully, he says, “there’s going to be an explosion in the East blocks today, sometime before eleven.”  
  
It feels someone’s dumped a bucket of ice water on Jinhwan. His first thought is that it should be _impossible_ , completely impossible, for anyone to know that. Nothing is making any sense. But then, gradually, it comes to him— Yunhyeong, who had studied physics for as long as Junhwe had, might know what Junhwe had.  
  
Jinhwan doesn’t know at what point Yunhyeong travelled back, and how, but it hardly seems to matter. The revelation ignites the first spark of real hope in Jinhwan since he’d come back here, to the facility, himself. If he and Yunhyeong share an objective, then Jinhwan isn’t alone in this.  
  
Jinhwan can barely get the words out. “Are you here to save Junhwe, too?”  
  
Yunhyeong had been one of the most easygoing guys Jinhwan had known in unversity— always smiling, always trying to make the best of any given situation. Right now, all traces of humour are gone from his eyes. Jinhwan has never seen him look more serious.  
  
“No,” Yunhyeong says. “I’m here to save you.”  
  
  
  
  
  
  
The boy who’s been watching Yunhyeong for the better part of the night looks like someone who might have attended lectures with him at university— intelligent eyes and a sharp face, matching Yunhyeong in age or maybe a year below. He’s one among a large group that had walked into the restaurant just after seven, making so much noise that Yunhyeong’s sister had rolled her eyes as she’d walked past to deliver a plate of meat to the next table. Over the course of his studies, Yunhyeong had grown used to the occasional bit of attention from girls in his classes; it’s probably for this reason that, half out of habit, he winks at the boy when no one is looking.  
  
He has to suppress a grin at the shock that passes over the boy’s face. The boy looks away, and Yunhyeong doesn’t think more about it for the rest of his shift. He doesn’t have the time to, what with the number of tables he has to serve— the week between Christmas and New Year is always an especially busy period, when he and his sister have to give their parents an extra hand around the restaurant.  
  
The rowdy group is the last of the night to leave. Yunhyeong tells the other wait staff to go ahead home, promises that he’ll clear the remaining mess and lock up the place. When he finally steps out to the reception area after changing out of his uniform, legs aching and backpack slung over his shoulder, the boy from before is waiting for him. He looks uneasy, which does nothing to ease Yunhyeong’s own apprehension.  
  
“Uh, hi,” says the boy, rubbing his hands together awkwardly. “I’m not here to take up your time, or anything like that. I just wanted to say sorry.”  
  
Yunhyeong raises an eyebrow. “For?”  
  
The boy blinks. “For… Wait, don’t you recognise me? It’s me, Donghyuk— Oh.” He reaches up and pulls his glasses off his face, folding the black frames in his hands and looking up at Yunhyeong expectantly.  
  
Yunhyeong still doesn’t recognise the person standing in front of him, nor does he recognise his name. There’s a chance Donghyuk had eaten at their restaurant and introduced himself in the past, though, so Yunhyeong decides to go along with it in the same of customer service.  
  
“Oh,” Yunhyeong says. “Don’t worry about it.”  
  
To his relief, Donghyuk looks relieved. He shoves his frames back onto his face carelessly and flashes Yunhyeong a wobbly smile. “I also wanted to say thanks. I realised I never did before, and… Yeah. I owe that much to you.”  
  
If he weren’t confused before, Yunhyeong definitely is now. For someone he doesn’t remember, Donghyuk sure seems to know a lot about this supposed history they share. Which is all very well, except Yunhyeong isn’t the type to forget people so easily. He knows the name of everyone who’s been a regular at the restaurant in the last two years.  
  
Donghyuk doesn’t seem to notice anything amiss. “If you want, maybe I could buy you coffee?” he ventures, a little obliviously. He must notice Yunhyeong’s frown, because he throws up his hands, almost defensive. “Not _now_. I mean some other time. When it’s less cold. And also less dark.”  
  
It seems like an innocent enough invitation. Yunhyeong casts his eyes upwards, as if considering the offer, but takes the opportunity to scan the ceiling for any hidden cameras. When this proves futile, he looks back at Donghyuk, who appears to be eagerly awaiting an answer. This whole situation is too much like a B-grade drama for his liking. Yunhyeong narrows his eyes. “Sorry, but I don’t actually know you very well…”  
  
Donghyuk looks stricken. “I don’t mean like a _date_ , I just wanted— I thought— You know what. Nevermind. Forget I said anything.” With a flustered noise, he turns around, wrenches the door to the restaurant open, and disappears into the night.  
  
After the door shuts, Yunhyeong stares at it for a good minute, pondering the absurdity of the encounter. He would have pondered it for longer, too, except Donghyuk comes back after the minute is up, seemingly having changed his mind.  
  
“Actually,” Donghyuk says, not even having the grace to look embarrassed. “Just let me get this off my chest. When are you free for coffee?”  
  
Which is how Yunhyeong ends up sitting across him two days later, in a coffee shop several blocks from the restaurant. Turning Donghyuk down would have been impolite, Yunhyeong reminds himself. It’s not his fault that Donghyuk is now just sitting in front of him, looking pensive and sad. Yunhyeong is past trying to understand him at this point.  
  
“You know,” Donghyuk says abruptly. “I was hung up over it for a long time. All I could think of was that if I’d done something differently, maybe… I don’t know. Maybe Junhwe wouldn’t have…” he sighs, eyes downcast.  
  
Yunhyeong suddenly feels a lot more unsettled than he had previously. “You worked with Junhwe?”  
  
Donghyuk nods. “In the same lab,” he says. “His space was right next to mine. We had lunch breaks together.”  
  
Yunhyeong recalls, almost too vividly, reading about the explosion for the first time. Heart thudding painfully in his chest, not daring to believing his eyes as he scanned through the list of the deceased. Koo Junhwe. The very same Koo Junhwe he had once done most of his lab work with, who hated morning lectures and always had something to say about the university’s fast food. Who decided in his second year that he would make it to a prestigious research company, but still spent more time texting Jinhwan than listening in class.  
  
Yunhyeong had gone to the funeral, far too late to regret a petty fight between them. Far too late to wish he’d been a better friend. As expected, Jinhwan had been uncontactable by phone, and impossible to talk to in person— Hanbin and Bobby never seemed to leave his side, standing on either side of him like bodyguards.  
  
Yunhyeong distracts himself from those thoughts by trying to connect the dots, to figure out the significance of Donghyuk knowing Junhwe to Donghyuk knowing him. But it’s like trying to assemble a puzzle with only half the pieces.  
  
“But I think I’m better now,” Donghyuk continues. “I’m getting better. I still feel like— But maybe things happen for a reason. I don’t know. I can’t imagine how Jinhwan must’ve felt.”  
  
Yunhyeong looks up so quickly that his neck cricks. “You know Jinhwan?”  
  
“Yeah,” Donghyuk is looking at him, head tilted. “I mean, sort of. He was there on the day of the accident. Didn’t you know that?”  
  
Yunhyeong shakes his head, trying to process the information. “What was he doing there?”  
  
Donghyuk looks thoughtful. “I don’t know,” he admits. “I never found out.”  
  
  
  
  
  
  
Yunhyeong is saying something. His mouth is moving, but Jinhwan isn’t listening to whatever he’s trying to tell him. All he hears is _I’m here to save you_. Another bombshell dropped. Another impossibility to add to the already long list of impossibilities he’d encountered that day.  
  
He struggles to find some sort of equilibrium, to make sense of the situation. Something, _anything_ , to account for this new development, to prove that he isn’t going completely insane. This is what it feels like to lose it, he realises, in a moment of dissociation. This is what it’s like to have a breakdown.  
  
Jinhwan doesn’t know what’s going on. Who’s supposed to be saving who. How to ensure that Junhwe will be okay.  
  
Maybe he sways, because he sees Yunhyeong move forward, almost reflexively, to steady him. There’s worry in his eyes, and— is that pity? It makes Jinhwan feel weak. Jinhwan is older than Yunhyeong, he’s supposed to be the one deciding what they should do next.  
  
Strangely, it’s the sense of obligation that snaps him out of it, makes him start pulling himself together. Bobby had always called him the responsible one. Jinhwan shouldn’t be thinking pessimistically and planning for worst-case scenarios, he can’t afford to give up now. No one is going to make sure Junhwe is safe, if not him.  
  
At the end of the day, it doesn’t matter who the accident killed, in which version of reality. The aim is to prevent it from happening entirely.  
  
“Jinhwan,” Yunhyeong is saying. “Are you okay? Can you hear me?”  
  
“Did you know about Junhwe’s research?” Jinhwan asks. To his relief, his voice doesn’t waver. “Is that how you got here?”  
  
Yunhyeong’s expression is guarded. When he opens his mouth to explain, he doesn’t quite meet Jinhwan’s eye. “I guess you could say that. I wrote some of it. At least, I did in the earlier stages. It was something we started working on together.”  
  
The news doesn’t incapacitate Jinhwan, so maybe he’s already getting better at this. He pushes aside the flood of questions that come to mind, among them _what happened after?_ and _why didn’t Junhwe ever tell me about it?_ , choosing instead to focus on what’s ahead. Every minute wasted is a minute that could be spent trying to find the source of the accident.  
  
“Let’s go,” Jinhwan says, and for the first time since morning, he feels like he— _they_ — can succeed. “Let’s figure out how to stop this. We only have—” He checks the time on his phone, heart dropping a little. It’s already well past ten. “We’re running out of time.”  
  
Yunhyeong’s eyes flash. “Have you been listening to me at all?” He takes a step so that he’s between Jinhwan and the door, as if ready to stop Jinhwan bodily from leaving the stairwell if he has to. “I’m not letting you go back out there. It’s too dangerous.”  
  
Jinhwan frowns, takes a half-step back. “That’s why you’ll help me, right?”  
  
The guilty look on Yunhyeong’s face is decidedly a bad sign. He raises a hand to scratch the back of his head. “Actually,” he says. “I can’t do that. I talked to a number of people on this floor, trying to figure out where Junhwe would be. Someone realised I don’t work here. They might or might not be looking for me as we speak.”  
  
Jinhwan stares at him, at a loss for words.  
  
“Stupid, I know,” Yunhyeong admits. “But I won’t be any help stopping whatever set off the explosion. And you can’t go out there alone. You might— You don’t know what will happen.”  
  
Something in Jinhwan flares up, a sharp retort ready on his tongue. For someone who had majored in science, Yunhyeong seems to have adopted a particularly short-sighted view on the matter. But the sensible part of Jinhwan knows he won’t convince Yunhyeong of anything this way, not by losing his temper. Objectivity and logic are the way to go.  
  
“Let’s say I don’t go out there,” Jinhwan says, voice carefully even. “Let’s say I stay away. I walk out of this building right now. What happens then?”  
  
And it’s that easy. Yunhyeong’s hesitation before he answers is palpable. “We never tested this— the time jumping. At least, I never did. I couldn’t tell you what would happen, not for sure.”  
  
“So you don’t know,” Jinhwan concludes. “You don’t know because you don’t know how this time travel thing really works. Both of us are here now, which means anything could happen, right? I’ve had this conversation with you, so I’ll be extra careful.” Jinhwan doesn’t like to feel like he’s manipulating anyone, but this is an unusually desperate situation. He looks Yunhyeong square in the eye, making sure to inject a slight tremble into his voice. “I have to stop the accident, Yunhyeong. It’s the only way to be absolutely sure nothing happens to Junhwe. I have to try.”  
  
It’s a miracle he manages to pull it off, considering how little control he seems to have had over his situation thus far. Yunhyeong sighs, resigned. “Junhwe’s evaluation is straight down the hall, in lab 7-G. It’s meant to start at half past ten.” He takes a long, hard look at Jinhwan. “If anything goes wrong, make sure you get the hell out of here.”  
  
“I will,” Jinhwan promises. He moves for the door, and Yunhyeong steps aside.  
  
“What about you?” Jinhwan asks. “What are you going to do now?”  
  
Yunhyeong looks towards the stairs. “I’ll look for Junhwe,” he says. “I’ll try and make sure nothing happens to him. Be careful, Jinhwan.”  
  
Jinhwan nods and steps back out into the seventh floor hallway. After the relative isolation of the stairwell, the feeling of being reconnected to the real world, with people going about their work and talking as they pass through the hallway, is a bit of a shock. Jinhwan tries to calm the anxiety coursing through him. He’s not doing anything wrong by being here. Not really.  
  
The first thing he does is walk to the end of the hall and look out the window. The main road is visible from this vantage point, along with a view of everything East of the PlanTech facility. Not too far away is the patch of green where the employees had gathered on the day of the accident.  
  
Hand to the glass, Jinhwan catches sight of a dark smudge colouring his wrist, and is momentarily distracted. It extends halfway down his inner forearm— A bruise, Jinhwan realises. He hadn’t noticed it there before, doesn’t remember hitting his arm against anything hard enough to produce a mark like that.  
  
But it’s not important right now. Back to the task at hand.  
  
There’s an unusually large tree next to the grass patch, one that seems familiar— Jinhwan must have passed it when he’d been wandering the area. He reverses the image in his mind, tries to recall what the building had looked like when he had observed it from the ground. Debris everywhere, the corner of the fourth floor blown out.  
  
Lab 7-G is the last along the stretch of hallway, closest to where Jinhwan is standing. From the outside, it looks identical to every other lab on the floor. Jinhwan pauses for a moment at the door, taking a moment to gather himself. He still has no real plan, but at least now he knows he’s not completely alone in this. If Donghyuk and Yunhyeong succeed, it might not even matter whether or not Jinhwan does.  
  
The time displayed on his phone reads two minutes to ten-thirty. Jinhwan raises his hand to the door and knocks.  
  
  
  
  
  
  
“So pretend you’re on a yacht,” Bobby is saying, his chopsticks pointed at Junhwe. “With Jinhwan, your mother, your, uh, roommate, and… Hanbin. And then, by some crazy stroke of misfortune, all four of them fall overboard at the same time. Who do you jump in and save first?”  
  
Junhwe looks extremely put-upon. Jinhwan is torn between laughing at the ridiculousness of the pseudo-interrogation, and jumping in to save him from his suffering. Bobby’s attempts to provoke some kind of a reaction out of Junhwe had almost worked initially, when Junhwe had still been intimidated, his heart set on making a good first impression. By now, Junhwe seems to have realised that nothing within the boundaries of ordinary behaviour is going to score him a place in either of Jinhwan’s friends’ hearts. That, or he’s decided Bobby is an idiot.  
  
Next to Bobby, Hanbin snorts into his soup. It’s like the two of them have some “Bad Cop, Good Cop” routine going on, except Hanbin is less Good than Entirely Unhelpful.  
  
“I can’t swim,” Junhwe says.  
  
Bobby looks disappointed, before the grin finds its way back onto his face. “Hypothetically, though? I mean, you’re not just going to _stand_ there. You can have a life buoy, if you want. Just one.”  
  
“Fine,” Junhwe fidgets in his seat. “Jinhwan, then.”  
  
Bobby looks shocked. “You’re not going to save your mom?”  
  
“She can swim,” Junhwe argues. “Really well. I know she can.”  
  
“Hanbin,” interjects Hanbin. “The right answer is Hanbin.”  
  
“But you don’t know if Jinhwan can swim?” Bobby asks, incredulous. “Do you know Jinhwan’s last name?”  
  
Junhwe looks like he’s trying hard not to roll his eyes, despite the faint tinge of pink now colouring his cheeks. His hand is resting on the bench between them, and Jinhwan reaches over to give it an apologetic squeeze.  
  
“Okay, that’s enough,” Jinhwan grins. “This isn’t productive. You,” he says, looking pointedly at Bobby. “Stop asking questions. Eat your food.”  
  
“But how will we know if his intentions are good?” Bobby exclaims, waving his chopsticks around and narrowly avoiding disfiguring Hanbin, who appears more invested in the meat on his plate than the conversation at hand. “How will we be sure he _loooves_ you?”  
  
Junhwe flushes red. “Washroom,” he announces as he stands abruptly, extricating his hand from Jinhwan’s grasp, if a little reluctantly.  
  
As he trudges towards the back of the restaurant and out of earshot, the shit-eating grin plastered across Bobby’s face changes into something softer.  
  
“You say you share a class with this kid?” he asks, leaning in conspiratorially. “Does he always look that pissed?”  
  
“No,” Jinhwan answers, taking advantage of Junhwe’s absence to put more food on the latter’s plate. “It’s just because of you.”  
  
Bobby looks satisfied.  
  
Hanbin shrugs. “I kind of like him.”  
  
Bobby rounds on him. “Why, because you’ve finally found someone who eats more than you? You're still the bigger pig, by the way. It’s about pace, not  quantity.” He leans back in his seat and crosses his arms, giving Hanbin a pointed look.  
  
“Anyone who doesn’t get along with him,” Hanbin jerks his head in Bobby’s direction, “is worth keeping around.” The words are directed at Jinhwan, and Bobby immediately sits back up.  
  
“I think Junhwe needs a little work,” he announces. “He’s alright, but I think with the right kind of training, he might not be such a killjoy—”  
  
“What does it matter what you think?” Hanbin shoots.  
  
Bobby blinks. “What is the point of us gathering here,” he says, drawing out the words. “If not to find out what I think about Junhwe?”  
  
“You invited us,” Jinhwan teases. “In fact, you made us clear our schedules for this. We were promised a free meal.”  
  
The banter carries on for a bit. Jointly, Hanbin and Bobby polish off a full serving of meat, and when Junhwe still hasn’t returned by the end of it, Jinhwan gets up to go check on him.  
  
The washroom at the back of the restaurant is no more than a single unisex cubicle. The door swings open when Jinhwan knocks.  
  
“Were you planning on coming back?” Jinhwan asks, trying to keep a straight face.  
  
Junhwe looks perfectly fine, if a little embarrassed. “Uh… Yes?” he tries.  
  
“Is it Bobby?” Jinhwan asks, more gently this time. “He’s always like that with new people, he doesn’t mean any harm. Just go along with it.”  
  
Junhwe nods, a show of compliance, but Jinhwan can read him better than that. “They like you,” Jinhwan assures him. “This isn’t a test, it’s more of a… formality. And even if they didn’t approve, they’d have no say.”  
  
Junhwe seems to perk up at this. “Really?” he asks.  
  
At times like these, Jinhwan is reminded that Junhwe is a whole three years younger than him. Not insecure, exactly, but less experienced. The difference is less magnified in other areas— Junhwe is, Jinhwan is sure, a good three years ahead of him when it comes to science.  
  
“Yes,” Jinhwan laughs, taking Junhwe’s hand to lead him back to the table. “Really.”  
  
  
  
  
  
  
“Come in,” says a voice. It belongs to a man who appears to be in his mid-thirties, who looks up from the clipboard he’s holding as Jinhwan enters the lab. He looks like he hasn’t slept in days, dark circles weighing down his eyes, hair hanging limp over his forehead. Jinhwan feels like he can relate.  
  
“Koo Junhwe?” the man asks.  
  
Jinhwan fingers the work pass hanging from his neck, photo face-down. “Yes.”  
  
The man, who must be Junhwe’s evaluation supervisor, nods his acknowledgement. Jinhwan shuffles deeper into the lab, trying to observe the equipment as discreetly as possible. Some of it is basic enough for Jinhwan to recognise from his days at university, but a lot of it isn’t. Assortments of gadgets and small machines litter the room. More pressingly, in cabinets along two of the four walls of the lab—  
  
Jinhwan draws in a breath.  
  
The supervisor seems to notice. “This used to be the main lab for chemical physics,” he explains, gesturing towards all the different bottles of chemicals lining the walls. “It moved upstairs, but some of the stuff is still leftover. Doesn’t matter, though. This lab works perfectly fine as a regular one.”  
  
This is where the accident happens, Jinhwan thinks. As long as there are chemicals in the room, any small mishap could end in a blast. If only there were some way to have the lab shut down for the day, or cordoned off…  
  
And then an idea comes to him. Jinhwan needs to get out of the room, set off the fire alarm. Get everyone safely out of the building. A flimsy plan, but worth a shot.  
  
“Koo Junhwe?” says the supervisor. “Are you ready for your evaluation?”  
  
And then there’s the question of how to get out without raising any suspicion. “Uh,” Jinhwan starts. His palms are slick with sweat. “Actually, I—”  
  
“Don’t be nervous,” the supervisor says, looking as though he wants nothing more than for this to be over quickly. It sounds more like the start of a script he’d memorised than a genuine offer of reassurance. “Standard safety protocol applies, I’m sure you’ve been briefed about what you’ll be doing. It’s pretty simple. You pass this and you’re all set, for another six months at least.”  
  
Jinhwan glances towards the door. Should he run for it, explain himself later? Would doing something like that hurt Junhwe’s reputation?  
  
“The setup’s over on that table,” The supervisor is saying. “I wanted to do a test round before you came in, so everything is on and running, but you’ll be doing your own—”  
  
He’s interrupted by a knock at the door. Jinhwan’s blood runs cold.  
  
“What the— does nobody know that this lab is— come in,” the supervisor calls.  
  
The head that sticks itself around the door doesn’t belong to Junhwe. Instead, it belongs to a young woman with short hair tucked behind her ears, and a playful quirk to her lips. Jinhwan feels himself  sag in relief.  
  
“Sorry to disturb,” the woman chirps. Her cheerfulness is jarring; Jinhwan had almost forgotten that this building is full of normal people, going about normal lives. The idea of someone having a good day probably shouldn’t be so surprising. “Head of the department wants to see you for a moment, Dr. Kwon. Something about lab maintenance. Says it’s urgent.”  
  
The supervisor— Dr. Kwon— looks exasperated. “Noted, thanks.” He goes over to the desk at the front of the lab and sets his clipboard down. “I’ll be there in a minute.” The woman flashes a thumbs up and closes the door.  
  
Dr. Kwon turns to Jinhwan. “Sorry, we’ll have to delay your evaluation a bit. Just… wait a little while for me to come back. I shouldn’t be long.” He takes a step towards the door, then doubles back, seeming to have remembered something. “Do me a favour and turn that off when it’s done,” he instructs, gesturing towards the evaluation setup. “It should be soon. But don’t stop it before then. Okay?”  
  
Jinhwan nods weakly, eyeing the different components of the setup at the station. An assortment of coloured wires run from what look like containers of chemicals, connecting at multiple points to two different machines stacked atop one another on the bench.  
  
Dr. Kwon leaves, door clicking shut behind him.  
  
It’s the perfect time for Jinhwan to carry out his plan, to go outside and set off the fire alarm. But something draws him towards the bench, like a moth to a flame. An unexplainable bad feeling in his gut that grows with every step.  
  
Up close, the setup looks even more impressive. Numbers flicker across the digital screens of the two machines— ammeter and voltmeter, Jinhwan identifies. Besides that, Jinhwan doesn’t know what the experiment is supposed to achieve, or when he’s meant to stop it. He hadn’t gotten to any of the classes on electrical circuits at university. High school physics doesn’t begin to explain all of this.  
  
If Jinhwan’s limited physics knowledge serves him, there’s a sizeable amount of electricity running through the wires. The experiment seems to be the only one going on in the lab.  
  
_This is it_ , Jinhwan thinks. _This is the source of the accident_.  
  
The time is ten thirty-nine. Jinhwan has minutes left, and he doesn’t know how many. He doesn’t want to touch the setup, not when he’d been told not to turn it off prematurely. And yet, leaving it alone would probably be equally likely to lead to an accident. What would Junhwe have done in this situation? What should Jinhwan do differently?  
  
Junhwe would never have gone for help. Which means that’s probably what Jinhwan should do. But he doesn’t know how much time he has left, and the prospect of taking matters into his own hands seems simpler, somehow. Breaking the circuit would have to stop the current. No explosion, no deaths. He’ll finally have his life back.  
  
Jinhwan raises a trembling hand to one of the wires, but then a thought crosses his mind: could halting the experiment, rather than leaving it alone, be what creates a lethal situation? A malfunction that would set off an explosion?  
  
He hesitates, and that’s when he sees it— one of the hanging wires with a segment of its casing worn and cracked, exposing the metal underneath. Every few seconds, a tiny spark shoots from the exposed section and falls, dissipating as it hits the floor.  
  
There’s really no reason to panic, except that at last, Jinhwan is almost certain he’s looking at what caused the accident. He takes a few involuntary steps back and turns, with the intention of leaving the lab to find help. As he does, his leg connects with something hard.  
  
Whatever it is knocks Jinhwan off-balance; he pitches forward, splaying his hands out at the last second to avoid colliding face-first with the linoleum. The rest of the shock is absorbed by his hip, sending a shooting pain up his side.  
  
Jinhwan winces, clamps down on the cry that bubbles its way up his throat. Moments later, there’s a _thump_ from behind him. Still on the ground, Jinhwan turns his head to see what he’d tripped over.  
  
The container, about the size of water dispenser bottle, must have been placed near the wall— Jinhwan hadn’t seen the label, had hardly noticed it was there at all. Now, it’s toppled onto its side, the impact having appeared to have caused the lid to burst open. A clear liquid is pouring from the container, out onto the floor.  
  
Jinhwan’s body reacts more quickly than his mind. He’s scrambling to his feet, ignoring the pain in his hip, before he can even register what’s happening. Up and onto the nearest bench. Out of reach of the spillage.  
  
He watches in horror as the liquid spreads across the floor.  
  
For a second, Jinhwan forgets what he’s supposed to be doing. A sharp, musty smell is filling the air, clouding his head. Then, with a jolt, he remembers. He looks back at the electrical setup, where a periodic spark bursts from the bit of exposed wire.  
  
It happens in slow motion.  
  
The spark floats downwards, like a leaf falling from a tree. Jinhwan traces its descent with his eyes, right to the point where it reaches the ground. The ground, which is now covered in the clear liquid.  
  
The spark touches the liquid, and ignites into a flame of brilliant orange.  
  
Not an explosion, but a fire. One that spreads across the lab just as the liquid had, rapid and threatening. Jinhwan leaps off the bench, nearly tripping over his own feet in his attempt to put as much distance as possible between himself on the fire. Deeper into the lab and further from the door. A good portion of the lab is now ablaze.  
  
Jinhwan can barely breathe. And that’s when he realises he’d been wrong all along. Carelessness, negligence, the electrical setup, the liquid, the spark— they’d all been ingredients in the whole disaster, but none one of them had caused the accident.  
  
_He’d_ caused the accident.  
  
  
  
  
  
  
“Yeah, I’m sure,” Bobby says, for the umpteenth time. “Hadn’t left the house in weeks, straight up disappeared. Nothing much is missing— just his wallet and phone. He’s not answering any calls, though. Hanbin is out of his mind worrying.”  
  
Yunhyeong swallows, pressing the phone closer to his ear. “When did you last see him?”  
  
“Uh… Three days ago,” is Bobby’s reply. “Wednesday? Yeah. I dropped by in the evening, Hanbin and I were both there the day before. We looked everywhere we think he could’ve gone… It’s like he disappeared into thin air.”  
  
“And the last time you saw him, he wasn’t acting strange, or anything?” Yunhyeong presses.  
  
Bobby is quiet for a moment. “No, not any more so than— what are you, a cop? Look, if you don’t know anything, it’s fine. I just called to check.”  
  
“I don’t,” Yunhyeong says quickly. “I haven’t seen Jinhwan since—”  
  
The line goes dead as Bobby hangs up.  
  
Yunhyeong lowers his phone from his ear, stares at the screen as the words _call ended_ flash briefly across it. Then he suppresses a sigh and locks it, wiping the screen clean on the leg of his jeans.  
  
Disappeared into thin air. It’s not like Jinhwan to let others worry about him, but then, it would be perfectly reasonable, considering what he’d been through recently. Something is nagging at Yunhyeong, though, something that has been bothering him since his meeting with Donghyuk.  
  
Donghyuk had claimed he’d seen Jinhwan on the day of the explosion. There are probably a hundred different reasons why Jinhwan could have been at the plant that day, but only one possibility— peculiar and outlandish— had stuck out to Yunhyeong.  
  
It’s a pretty ridiculous theory. Yunhyeong isn’t even sure if it’s possible, which is probably what makes it such a compelling one. He thumbs through his contacts list, selecting Jinhwan’s number and raising his phone to his ear.  
  
The call goes straight to voicemail. Nothing unexpected.  
  
He tries a different contact.  
  
Donghyuk picks up after two rings. “Yunhyeong?” he says, surprised. “I didn’t think you’d ever need my number. What’s up?”  
  
For some reason, Yunhyeong is relieved to hear his voice. “I need to ask you something. This might sound strange, and I’m sorry to bring it up again, but… What do you remember about Jinhwan, from the last time you saw him? At your workplace. That day.”  
  
Donghyuk is silent for a while. “What do I remember about Jinhwan? Like… he was kind of on the small side, under one seventy? And he looked sick, I thought maybe he’d caught the flu or something. It was pretty cold…”  
  
“No, not that,” Yunhyeong spares a glance at the clock mounted on the wall, trying to estimate how much time he has before his sister comes into the back room looking for him. “I mean, was he behaving strangely in any way?”  
  
“What, like singing the national anthem while crawling around on all fours? You might want to be a bit more specific? He wasn’t doing either of those, though.”  
  
Were they in any other situation, Yunhyeong might have laughed. As it is, he can feel a sense of foreboding beginning to make its way over him. “I mean, did he say anything that came across as strange? Did he seem to know anything he shouldn’t have known?”  
  
Donghyuk goes silent for another few seconds. “Why are you asking me all this?”  
  
Yunhyeong closes his eyes, takes a deep breath to collect himself. “Just answer the question. Please.”  
  
“He was acting like you’re acting right now,” Donghyuk sniffs. “Asking me questions, asking me to do things, and then not telling me anything.”  
  
Yunhyeong immediately feels bad. Donghyuk is an innocent, a bystander who had already lost a colleague in the accident. Who, by the sound of it, believes he’s partly to blame. He deserves an explanation. One which, unfortunately, Yunhyeong currently has neither the time nor answers to be able to give.  
  
“If I figure this out, I’ll explain everything,” Yunhyeong promises.  
  
Donghyuk seems to accept the poor attempt at a fair trade. He makes a thoughtful noise. “He didn’t seem to know Junhwe was quitting, but… he did ask me to try and keep Junhwe away from the East block,” he says. “Which was pretty, well, strange, like you said. But that’s about it.”  
  
“Thanks, Donghyuk,” Yunhyeong says, voice tight. His suspicions might be right, after all.  
  
It’s almost six, which means the restaurant will start getting crowded soon. Once that happens, it will be impossible to sneak out.  
  
As he leaves from the back, heading in the direction of the station, Yunhyeong composes two texts— one to his sister, claiming a migraine and apologising for leaving her to take over his share of work for the night, and one to Bobby, asking for directions to Jinhwan’s apartment.  
  
If there’s something to be thankful for, it’s that he manages to avoid peak hour on the train, making it to the apartment in under an hour. Bobby answers the door, one hand on the phone at his ear, talking heatedly to the person on the other end of the line. Yunhyeong places the bags of takeout he’d bought on the way on the dining table. Hanbin is nowhere in sight.  
  
With Bobby distracted, Yunhyeong makes a beeline for the bedroom.  
  
Nothing seems unusual, besides the fact that the room looks like it hasn’t been inhabited in ages. Everything is a touch too neat, unlived in. There’s a box atop the desk, which appears to contain several items belonging to Junhwe. Yunhyeong picks up a notebook, turns it over in his hands so that he can see the logo.  
  
SK PlanTech. The grief hits him with a pang then. Junhwe had been someone he’d spent the better part of his university days with, with whom he had pulled all-nighters in the library with and dragged with him to lectures the next morning. They’d shared classes, ideas, a dream. Had a falling out that shouldn’t have lasted nearly as long as it had.  
  
And now Junhwe is gone. For no reason that Yunhyeong can fathom. Without any warning.  
  
And so is Jinhwan, from the looks of it. Unless Yunhyeong’s hunch is right, and there’s still a chance to change things.  
  
It takes almost ten minutes of searching for Yunhyeong to find what he’s looking for. He’d originally been trying to move the bed slightly to get to the space between it and the wall, apparently forgetting the fundamentals of physics in the process. He heaves, and only the top half of the bed budges. And there, wedged between the mattress and bed frame, is what appears to be a small stack of papers.  
  
  
  
  
  
  
Jinhwan watches mutely as the fire reach the first cabinet, the flames licking their way up the sides. He can’t move. There’s a layer of glass separating the fire from the assortment of bottled chemicals— will that be enough? He must have been through so many lab safety briefings at university, must have been taught something that would help in a situation like this. But even though he’d always been attentive in class, Jinhwan’s mind is completely blank.  
  
The lab is quiet, save the soft crackle of the growing fire. For a split second, everything in the room seems almost calm.  
  
The blast is sudden, with no real warning. There’s a blinding flash, a rush of heat, and then Jinhwan is knocked backwards, off his feet. He feels the back of his head connect with something as he falls.  
  
There’s a burst of stars in his vision, and for a terrifying few seconds, it’s as if Jinhwan is in a void, disconnected from reality. His vision is white, along with the noise that fills his ears. He can’t feel any of his limbs. Panic grips him, the fear like a chokehold.  
  
His senses return to him slowly— first the indistinct sound of something high-pitched, growing progressively louder. A ringing in his ears. No, Jinhwan realises, not a ringing in his ears. An alarm. The fire alarm. It sounds like someone is screaming too, but it’s so faint that it can’t be anyone in the immediate vicinity. Someone outside, maybe. Someone outside is screaming.  
  
His vision is next, a blur of colour that gradually comes into focus, producing a shaky picture, fuzzy at the edges. The floor isn’t where he’d expected it to be. Jinhwan blinks, trying desperately to reorient himself. He’s slumped against a bench, and he’s looking at the windows. His head spins. A little over to the left— there it is. The blast had torn apart a portion of the wall separating it from the hallway. From this angle, some of the damage is blocked by the surrounding benches, some by the smoke billowing from the wreckage. Somehow, Jinhwan registers blackened, jagged edges of concrete.  
  
Finally, he regains the ability to process things. A single thought had crossed his mind as he’d been knocked to the floor by the blast— _this isn’t it_. He’d lost it briefly in the aftermath, but now the implication returns. The explosion reported in the news, the one he’d been trying to stop, had decimated a large chunk of the building. Right now, the outer walls of the lab are still intact. Jinhwan is worse for wear, but still very much alive. So this blast, this small blast, can’t have been the same one. This isn’t it.  
  
Then the pain hits him. Not so much a wave of it as a dull throbbing that grows, until it’s far too excruciating to ignore. Like a particularly bad body ache post-illness, but magnified tenfold. What he’d felt from his fall earlier had been nothing compared to this— Jinhwan squeezes his eyes shut, trying to steady his breathing. He’s suddenly aware that the room is hot, so hot that it feels like his face might begin melting at any moment. His head feels light and heavy at the same time.  
  
He tries wiggling his fingers experimentally, but it’s as if his muscles are no longer under his control. He still can’t feel his body. It’s a good thing smoke rises, Jinhwan thinks faintly, because it doesn’t look like he’ll be going anywhere anytime soon. Is this how he dies? Paralysed, helpless, as the fire continues to rage around him.  
  
But he can’t give up so easily. Not yet.  
  
Jinhwan takes in everything around him, tries to find something that might help him out of the situation. The smoke has thickened; it clogs the air above Jinhwan, obstructing his vision. His eyes are beginning to smart.  
  
That’s when he catches sight of the gaping hole in the floor. Only part of it is visible from his position, but it’s unmistakable— there’s light grey linoleum, and then there’s nothingness. The blast hadn’t just destroyed part of the wall. The screams had come from below, Jinhwan realises, from the lab directly underneath this one.  
  
More worrying is the large crack that runs from the site of the blast, through the floor and ending inches from where Jinhwan is propped.  
  
The floor isn’t crumbling. Not yet. But it looks like something that could happen at any moment, and if it does— a plummet to the floor below, with no way to brace his fall.  
  
Jinhwan feels his heart rate speed up, breath coming out in gasps. _Move_ , he thinks, and maybe it’s sheer desperation that reboots his motor neurons, but only enough that his arm spasms. Concentrating with everything he has, Jinhwan manages to draw his legs in, away from the crack in the floor. Every bit of movement is exhausting, like trying to run through quicksand.  
  
Parts of the floor are falling away, starting with the area nearest the cabinet. He has seconds, maybe, before the destruction reaches him. Jinhwan angles himself away from the bench, pushes himself backwards. Slowly, steadily. But the progress he’s making isn’t enough. Pieces of the floor are breaking away, sending puffs of white dust into the air.  
  
Ten seconds till the ground under him crumbles. Five seconds. Three—  
  
Jinhwan closes his eyes, braces himself for the fall.  
  
It happens fast. He hears a crash before he feels someone grab him from behind, yanking him backwards. Across the floor and out of danger. Jinhwan’s eyes fly open. The spot where he’d been sitting, just seconds previous, no longer exists.  
  
Whoever had grabbed Jinhwan pulls him far away enough from the wreck that it seems safe, leans him up against another bench. Kneels down so he’s level with Jinhwan. Jinhwan knows who it is before he sees him.  
  
“Are you okay?” Junhwe asks, concern etched on his face.  
  
He’s wearing a shirt Jinhwan had bought him when they were still at university, his hair tamed down with wax— He looks exactly as he had on the morning of the accident. Which had been this morning, technically. To Junhwe, it would only have been hours ago. But to Jinhwan it had been weeks, maybe months. It had felt even longer than that.  
  
Jinhwan tries to swallow the lump in his throat. His chest feels tight. Junhwe’s hand on his shoulder is a solid weight, completely real. Here, Junhwe is alive.  
  
Jinhwan can’t go back to a future where he’ll never see Junhwe smile again, where there’s no reason to drag himself out of bed every morning when the sky is still dark. A future without the familiar weight next to him at night, where the dishes do themselves and there are no work-free weekends with Junhwe to look forward to. One where Junhwe is nothing more than a memory, someone Jinhwan will only ever see in his dreams. Jinhwan realises it as he looks at Junhwe, whose face is unusually pale, eyebrows drawn together in worry. Jinhwan can’t do it. Junhwe matters too fucking much.  
  
Junhwe’s expression morphs into one of surprise, and that’s all Jinhwan remembers before Junhwe blurs and goes completely out of focus. There’s a noise— a high-pitched, broken-sounding thing— and it takes a moment for Jinhwan to realise it’s coming from himself. The next thing he knows, Junhwe’s arms are wrapped around him, and he’s bawling into the front of Junhwe’s shirt.  
  
“Don’t… cry,” Junhwe says, so awkwardly endearing that it only makes Jinhwan cry harder. Every bit of upset he’d kept bottled up since the accident, all the grief and the guilt, all come flooding out. It’s stupid, but it’s like nothing else matters in that moment— not the accident, not the fire around them. Not when Junhwe is here in front of him. Jinhwan tries to stop— he knows Junhwe hates it when he cries— but it’s about as useful as trying to swim against a strong current. Jinhwan can’t help it.  
  
Junhwe rubs soothing circles onto his back, waits for him to calm down. Jinhwan doesn’t know for how long. When he eventually quietens to a sniffling, Junhwe pulls away.  
  
“We need to get out of here,” he mutters, keeping a reassuring hand on Jinhwan’s shoulders while making to stand. For some reason he winces and aborts the action, instead choosing to survey their surroundings from a kneeling position. He’s injured, Jinhwan realises. An almost grotesque-looking burn colours his thigh through the material of his pants.  
  
Guilt is nothing unfamiliar at this point. Once again, Jinhwan had been too absorbed in his own problems to notice other, more important things. The wound on Junhwe’s thigh looks fresh, a bright, angry red. Jinhwan’s eyes water just from looking at it.  
  
“You’re hurt,” Jinhwan says weakly. “Did you get that when you came in?”  
  
Junhwe nods absently, still looking around. “Blocked,” he mutters, running a frustrated hand through his hair. “Everything’s blocked, there’s no way we can—” He seems to notice the way Jinhwan is looking at his injury. “It’s fine, it doesn’t hurt that much.”  
  
He sounds so self-assured that Jinhwan is almost convinced. They’re waging a battle on Junhwe’s turf, Jinhwan realises— Junhwe’s workplace, half of what had made up his life. In a situation made possible by Junhwe’s own research. Jinhwan swallows, forcing himself to take his eyes off Junhwe’s thigh. There’s something else that’s been nagging at him, ever since Junhwe had all but materialised to save him.  
  
“You’re not surprised I’m here,” Jinhwan says.  
  
Junhwe avoids his eye, but Jinhwan reads discomfort in the slight stiffening of Junhwe’s shoulders, the way his fingers twitch. “I met Yunhyeong on the way here,” he says, as if that’s enough of an answer. Except for one detail: Yunhyeong had been meant to help keep Junhwe away, not the other way around.  
  
“Did he tell you to come here?” Jinhwan asks, uncertainty beginning to work its way through his body.  
  
Junhwe looks surprised. “No,” he says quickly. “Of course not.” He seems to hesitate before continuing. “We developed the research together, for a few years. Then he wanted to stop. Said it was too dangerous.”  
  
Jinhwan nods, the gears in his head turning. Junhwe had always been fiercely determined— or stubborn, depending on how you looked at it. He had also stopped talking to Yunhyeong shortly after graduation.  
  
Junhwe’s eyes are on the ground. “At first, I thought this whole thing was his idea, that he brought you here. But that’s not true, is it?”  
  
Jinhwan shakes his head. “No.”  
  
Junhwe seems to relax. He pulls himself over to where Jinhwan is, leaning beside him against the bench. “Yunhyeong was right,” Junhwe laughs, humourless. “I fucked up. I should’ve stopped when he told me to. I couldn’t tell you, Jinhwan, not once I figured it out. It was too dangerous. Do you know how it works?”  
  
Jinhwan’s mouth is dry. “I didn’t,” he says. “But I think I do now.”  
  
Junhwe looks away. “Then you already know how this ends. The physical chem lab is directly above us— I can’t carry you, not with this leg. There’s nowhere to go, anyway.”  
  
Jinhwan is well aware that death might only be a minute away. In this moment, though, there seems nothing more tragic than seeing Junhwe look so lost. There’s something about hopelessness that doesn’t sit right on Junhwe. Junhwe makes mistakes— they both do— but he never stops trying, never backs down from fighting for what he wants. The look of utter defeat on his face frightens Jinhwan, possibly more than the prospect of the accident itself.  
  
The fire has all but engulfed the side of the lab closest to the hallway, a wall between them and the rest of PlanTech. Jinhwan reaches over, takes Junhwe’s hand in his. He wants to tell Junhwe everything he’d failed to the last time, but he doesn’t know where to begin.  
  
What comes out of his mouth instead is, “I heard you’re quitting.”  
  
Junhwe sits up a little straighter. He looks surprised, but doesn’t ask any questions. Maybe he’s already figured it out.  
  
“I like this job,” Junhwe admits. “But we don’t get enough time together.” He looks embarrassed at the admission, almost as though he hadn’t meant to say it. “I checked out other options— they’re a lot more flexible, less intensive. Not as prestigious, obviously, and the pay’s nowhere close, but I’d have more time outside of work. That’s what I want. More than I want to be here, I guess.”  
  
Jinhwan doesn’t cry, he can’t start again, but the knot in his throat is tight. For the first time, he feels something besides guilt flare up in him— a sort of righteous indignation on Junhwe’s behalf. If only Bobby, Hanbin, Yunhyeong, everyone who had ever made an off-handed remark about Junhwe being the relationship’s obstacle, could only understand this for themselves. Junhwe is selfless, caring. Jinhwan had been stupid to have doubted it, to have ever thought otherwise.  
  
“I knew you would’ve been upset if you found out,” Junhwe continues. He’s right, of course. Jinhwan would never have agreed to the compromise. Junhwe scoots a little closer to him, so that he’s practically pressed up against Jinhwan’s side. “But life’s too short for regrets, right?”  
  
There’s nothing quite like being trapped in a burning building to magnify the complete truth in the statement. No one wants to die. Junhwe is brilliant, has a promising career laid out in front of him regardless of where he works. Junhwe deserves so much better. Jinhwan, maybe less so, but it’s not an easy feeling to describe, knowing that you’re facing the end. Jinhwan isn’t above admitting it. He’s scared.  
  
“I’m sorry,” Jinhwan whispers. “I wish things were different. You’re so important to me, Junhwe, and I just…” he gives Junhwe’s hand a squeeze, in some naive sort of hope that Junhwe will understand what he’s trying to convey. “You know?”  
  
When Junhwe smiles at him, it’s just like the very first time they met. “I know,” he says. “I love you, too.”  
  
The flames have reached the ceiling, incinerating the cabinets in their wake. In slow motion, a section of the ceiling gives way, giving the fire a clear path in.  
  
Like the first blast, the explosion goes off without much warning. Unlike it, this one makes the first look like child’s play; there’s a flash of bright, brilliant orange, rolls of dark smoke billowing from the upper floor. A deafening rumble accompanies it. And then a searing heat envelops the room— burning, impossibly hot.  
  
Junhwe’s hand is gripped tightly in his. Jinhwan feels the world being ripped apart around him, and then everything goes white.  
  
  
  
  
  
  
_“…Witnesses reported hearing a blast following the sounding of the alarm. As of now, five of the deaths are suspected to be employees at the facility, with one body as of yet unidentified. The confirmed victims include Park Byungjun, Lee Jaemin, Koo Junhwe…”_  
  
  
  
  
  
  
They’d stood facing each other two years ago, a meter and a small stack of research separating them. There had been something in Junhwe’s eyes, fierce and determined, that had scared Yunhyeong.  
  
It’s not too different from the look in his eyes now, crossing the first floor reception area of the building, right before he catches sight of Yunhyeong emerging from the East block lift lobby. A look passes over Junhwe’s face. Shock, pure and unadulterated. It’s gone in a second.  
  
Yunhyeong lets Junhwe walk up to him. “What are you doing here?” Junhwe hisses.  
  
He hasn’t changed. Same grumpy expression, same brashness. It feels like a dream, to see him alive and healthy, after having attended his funeral.  
  
Yunhyeong doesn’t have a good answer to his question. For all that he’d expected to be up against by returning here, to this timeframe, he’s unprepared for this particular conversation.  
  
_I’m not sorry, but I wish we didn’t argue_ is the first thing that comes to mind. “I work here,” is what comes out instead, and from the flash of discontent in Junhwe’s eye it’s apparent he doesn’t buy it. “Didn’t you know?”  
  
Junhwe scowls. “Were you upstairs? How did you get in?”  
  
It had never been in Junhwe’s nature to be trusting, and their history had probably reduced any chance of Junhwe ever listening to him without question to zero. Still, Yunhyeong decides to try his luck. “It’s a long story,” he says. “I’ll tell you if you come with me for a bit.”  
  
Junhwe eyes him warily. “No, I have somewhere to be.” He pulls his phone from his pocket to check the time. “Thanks to someone, I’m already late.”  
  
“Don’t,” Yunhyeong says, before he can think it through. “You can’t up go there. It’s dangerous.”  
  
Junhwe takes a step back, fixes Yunhyeong with a gaze that’s half frustration, half interest. “Why do people keep _saying_ that? Do you know something I don’t?”  
  
Yunhyeong swallows, raises a hand to scratch the back of his head. A nervous habit. “If you want the truth—”  
  
He doesn’t realise Junhwe moves, only sees Junhwe’s arm dart out and feels Junhwe’s fingers wrap around his wrist. Yunhyeong jerks forward as his arm is pulled, twisted, but not in a way that hurts. For a second, he thinks Junhwe has finally cracked, is finally resorting to physical violence to get answers. Then he realises— Junhwe had grabbed him to get a proper view of the underside of his arm.  
  
A bruise runs the length of it, a blotchy, ugly purple. Yunhyeong stares with Junhwe. It hadn’t been there before, he’s certain. Surely, he would have noticed or felt it. He hadn’t done anything that could have resulted in such a crude-looking injury, either.  
  
_Side effect_ , whispers the voice in his head.  
  
“What happened to your arm?” Junhwe asks. But he knows, Yunhyeong realises, as he watches the myriad of emotions that flicker through Junhwe’s eyes. Confusion, apprehension, and finally realisation. It takes almost a full minute, but Junhwe knows exactly what it is.  
  
“You didn’t,” Junhwe says.  
  
Yunhyeong had been the one to do the research, to thrust it in Junhwe’s face during that final confrontation. Travelling outside of the usual space-time continuum could do unpredictable things to the body. It's inevitable. Symptoms, in the best-case scenario. Degeneration, in the worst. It's too dangerous. Far, far too dangerous.  
  
Yunhyeong says nothing.  
  
“You couldn’t have,” Junhwe continues, disbelieving. “It wouldn’t work.”  
  
Yunhyeong licks his lips. They’re dry, chapped. “But I did,” he says. “So it must have worked.”  
  
Junhwe shakes his head, releasing Yunhyeong’s wrist and taking a step back. He looks at Yunhyeong like he’s seeing him for the first time. “No, that’s not what I mean.” He seems to deliberate for a moment. “Theoretically, you could jump, but…”  
  
“But what?” Yunhyeong asks, chest tight with anticipation.  
  
Junhwe blinks. “But you wouldn’t be able to change anything,” he finishes. “That’s the whole problem with jumping back. That’s why nothing came out of everything we did. It’s pointless. It would create a paradox.”  
  
For all that space-time manipulation is meant to be infeasible, it seems like time has slowed.  
  
And finally, everything makes sense.  
  
Yunhyeong never really had a chance at saving Jinhwan. He never had a chance at saving Junhwe. There’s only one timeline, in which Jinhwan returns, and so does Yunhyeong, and together they try to stop the inevitable. Inevitable, because they’d helped cause it.  
  
“God,” Yunhyeong whispers, entire body numb. “I was right, it’s so dangerous. It’s even worse than I’d thought.”  
  
Junhwe has that look in his eye, the one that means he has an endless number of questions, but no idea how to go about asking them. He opens his mouth—  
  
—and a shrill sound cuts through the air, so piercing that Yunhyeong jumps.  
  
The fire alarm.  
  
Junhwe jerks, startled. For moments, nothing appears to have changed. Then the alarm rings a second time, equally shrill, and the receptionist at the far end of the lobby gets to her feet. Junhwe glances towards the East block lobby.  
  
“Don’t,” Yunhyeong warns, in a last-ditch attempt to avoid the unavoidable. “Stay away from there, Jinhwan wanted—”  
  
A mistake. Yunhyeong realises too late that Junhwe isn’t supposed to know anything about Jinhwan’s involvement in this. Junhwe goes white.  
  
“What,” he growls, voice so low it’s almost inaudible. “Did you say?”  
  
Yunhyeong shuts his mouth. If he’d thought Junhwe had been riled up earlier, he’d been wrong. Junhwe is positively bristling now. Yunhyeong has never seen him look so angry.  
  
“If you brought Jinhwan with you—” Junhwe starts, but he’s interrupted by a loud chime, followed by a pleasant female voice, projected from the building’s announcement system.  
  
_“Your attention please. The fire alarm has been activated. Please evacuate the building via the nearest emergency exit, and do not use the elevators. We are currently investigating the source. Thank you.”_  
  
Junhwe turns to Yunhyeong. “Where is he?” he demands. “I have to go before— before my colleague finds me.” Already there are employees beginning to emerge from their respective lobbies, wandering into the reception area with varying levels of surprise on their faces. Yunhyeong wonders for a moment whether there would be any point in withholding the information.  
  
But once again, he’d probably do the same as Junhwe, were their positions reversed.  
  
When he answers, Junhwe’s lips thin. Simultaneously, there’s a shout from the West side of the building— Donghyuk is making his way over, eyes fixed on them, frantically trying to push past the growing crowd of employees streaming towards the exit.  
  
Junhwe turns and bolts for the East block. Yunhyeong stays rooted to the spot. As Donghyuk tries to pass him, Yunhyeong grabs him.  
  
“Let me go,” Donghyuk gasps. “I can’t let Junhwe— he’s going to— let _go of me_ —”  
  
But Yunhyeong can’t. He’d already sent two of his friends to their deaths. One completely by accident, the other less so. He feels the bile rising at the back of his throat, a burning guilt snaking its way through him. His fault. And yet, there’s someone he can save. Someone he’s meant to save.  
  
“Sorry,” Yunhyeong bites out, through gritted teeth. “I can’t do that.”  
  
  
  
  
  
  
Jinhwan is taking a break from practicing a new routine when his phone flashes, indicating an incoming call from an unknown number.  
  
"Jinhwan?" says the voice at the other end of the line, shaky and distorted with poor reception. "Where are you? I… I couldn’t get to him."  
  
The voice is unfamiliar. "Uh," Jinhwan racks his brains for something he might have forgotten, tries to situate the person’s words in some sort of context. His mind comes up blank. "Get to who? Who is this?"  
  
"It's me," the voice is noticeably urgent. Jinhwan is beginning to think he hadn’t imagined the hysteria there, that it’s not just the result of static. The person on the other end of the line sounds panicked and short of breath. "It's me, Donghyuk."  
  
"Donghyuk?" Jinhwan quickly runs through a mental list of some of his closer friends from middle and high school. The name doesn’t ring a bell; he’s fairly certain he doesn’t know a Donghyuk.  
  
“I couldn’t get to Junhwe. I think he—” the rest of Donghyuk’s words are indecipherable, drowned out by the sounds of raised voices in the background.  
  
“What?” Jinhwan asks, heart skipping a beat. “What happened? Is Junhwe okay?”  
  
And then the name clicks. Jinhwan _does_ know a Donghyuk. He’s Junhwe’s colleague, the one who apparently doesn’t know how to shut up, but also regularly covers for any screw ups Junhwe makes in the lab. Junhwe has talked about him on multiple occasions.  
  
“Explosion,” Donghyuk says, voice wavering. “In the East block. Didn’t you hear?”  
  
  
  
  
  
  
Morning rush hour is the worst time to be taking the train anywhere, let alone to the university station. The time on Jinhwan’s phone reads five minutes to nine; he had initially thought his lateness would at least mean an easing crowd, that maybe for once he wouldn’t end up being trampled by eager first years before even setting foot on campus. Now that he steps onto the platform with about a hundred others jostling for the exit, however, he remembers that the tardiness of university is inescapable.  
  
The crowd forms a bottleneck at the stairs, and someone particularly enthusiastic about making it to class shoves Jinhwan to get past. The timing is unfortunate; Jinhwan is caught mid-step, one foot off the ground, and the impact sends him off-balance and careening into the person to his right. Carried by the momentum, Jinhwan knocks the person off course with him, straight into the wall of the station.  
  
“Sorry,” Jinhwan yelps once he’s regained his balance, frantically jumping back and out of the person’s personal space. “That was an accident— I was pushed and— sorry.”  
  
“What the fuck,” is the unenthused, boyish reply. “Watch where you’re— oh, hey.”  
  
Jinhwan raises his head to get a look at the person he’d accidentally assaulted. The boy looks to be a student in his first or second year, with a style Bobby would probably call “hip-hop” and Hanbin would probably call “boring”. He’s tall, in an annoyingly attractive way, with slightly more than half a head on Jinhwan. All traces of irritation on the boy’s face seems to vanish the instant Jinhwan makes eye contact with him.  
  
Jinhwan frowns, perplexed by the reaction. “Hey?”  
  
The boy blanches, then averts his gaze. “We’re, uh, in the same naming theory class. The one on Thursdays? You were… a few seats from me in last week’s lecture.”  
  
Jinhwan studies the boy’s face. “Oh,” he says after a second. “I remember you. You’re the… coffee… guy. The one with the coffee.”  
  
The boy looks mortified.  
  
Jinhwan gestures to his once-white sneakers. “I haven’t had the chance to try washing the stains out… but don’t worry about it. They have more character now, or so I’ve been told.”  
  
The boy flushes, nodding awkwardly. Jinhwan glances towards the stairs, which are now almost empty. “Well, it’s Thursday, so we can walk to class together?”  
  
The boy nods again, surprised. “Come on,” Jinhwan says. “Let’s go, before the next train gets here.” As he turns, he hears the boy mutter something behind him. Jinhwan only catches the words _do-over_.  
  
“If only it were possible,” Jinhwan says, without really thinking.  
  
“It could be possible,” the boy mumbles. “Someday.”  
  
Jinhwan stops in his tracks, turning and thrusting his hand out at the boy. “Speaking of which,” he says. “I’m Jinhwan. Kim Jinhwan. Nice to meet you.”  
  
Once again, the boy looks taken aback. But he reaches out, takes Jinhwan’s hand firmly in his. A slow smile spreads across his face. It’s a nice smile.  
  
“Junhwe,” he says. “Koo Junhwe.”

**Author's Note:**

> The idea behind the [Novikov self-consistency principle](https://en.wikipedia.org/wiki/Novikov_self-consistency_principle) is that you cannot change the past in any way, because if you do, the sequence of events that led to you travelling back in the first place would no longer exist. Rather, travelling back would lead to you contributing to the events, creating a paradox – Jinhwan travelled back in time because the accident took place, but at the same time the accident took place because Jinhwan travelled back in time.


End file.
